The Big Ten outlined its decision to punish the University of Michigan and Jim Harbaugh in a series of documents released on Friday afternoon, including a 13-page letter to Michigan officials that gives step-by-step insight into the league's decision-making.

On Friday, the Big Ten announced that it was suspending Harbaugh from coaching for the remainder of the regular season as punishment for the football program violating the conference's sportsmanship policy.

Big Ten commissioner Tony Petitti said he believed immediate action was necessary because of "the extraordinary nature of the offending conduct."

In the letter, which is addressed to Michigan athletic director Warde Manuel, the sign-stealing scheme allegedly organized by former Michigan staffer Connor Stalions is termed as an "organized, extensive, years-long in-person advance scouting scheme that was impermissible."

Later in the letter, Petitti writes that evidence gathered by the NCAA and corroborated by other Big Ten members leads him to believe that a significant portion of the violation has been "proven," with details of scope, intent and individual knowledge yet to be determined for potential additional penalties.

Petitti's letter directly addresses several of the issues raised by Manuel and Harbaugh's attorney in letters that they sent to the league office on Wednesday. Petitti lays out his justification for a punishment while hitting on themes by detailing the evidence he's seen, his interpretation of the league's bylaws and a pressing need for fairness in the race of a scheme that he says "compromises the integrity of competition."

"Competition that is only about winning while disregarding the rules of fair play diminishes all of us, including our institutions," Petitti wrote. "The integrity of the competition must be preeminent."

Michigan president Santa Ono said Friday evening in a statement that he was dismayed by Petitti's "rush to judgment" and accused him of reacting to pressure from other conference schools. Ono said Michigan plans to pursue a court order to keep Harbaugh on the sidelines Saturday, and that he believes the timing of the Big Ten's decision was intended to hurt the school's chances in court.

"By taking this action at this hour, the Commissioner is personally inserting himself onto the sidelines and altering the level playing field that he is claiming to preserve," Ono wrote. "And, doing so on Veterans Day -- a court holiday -- to try to thwart the University from seeking immediate judicial relief is hardly a profile in impartiality."

Petitti said in his letter that it was notable that Michigan was not denying the existence of an impermissible scheme but "instead it offers only procedural and technical arguments designed to delay accountability."

Petitti wrote that he first learned the NCAA was investigating Michigan during a phone call on Oct. 18 set up by NCAA president Charlie Baker. Baker's personal concern, Petitti said, gave him additional cause for concern. He said during subsequent videoconferences with the NCAA he viewed images of a "master spreadsheet" that Stallions used to coordinate which games his network of helpers were attending in his video-gathering scheme.

Petitti said the conference also gathered more information from its other member schools that corroborated evidence the NCAA had shown him. Based on the evidence they have gathered, the NCAA has informed the Big Ten that the existence of an impermissible scheme was "uncontroverted," according to Petitti's letter.

Friday's letter by the Big Ten says "the conference takes exception" to Michigan's assertion in its letter this week that its concerns are based largely on "rumors."

Michigan also argued in its letters to the Big Ten earlier this week that the conference was ignoring due process and was bound by Big Ten bylaws to allow the NCAA investigation to conclude before taking any action. Petitti rebuked this argument in his letter Friday, saying the Big Ten's sportsmanship policy provides "wide discretion" and is separate from another part of the league's rulebook, which defers to NCAA investigations.

Petitti wrote that the Big Ten's rules "could not be clearer" when it comes to his authority to act by using the league's sportsmanship policy.

"When sportsmanship issues, including the integrity of competition, are implicated by the offensive conduct, the Commissioner is authorized to use the procedures and authority prescribed by the Sportsmanship Policy, even if that offensive conduct also may involve a violation of NCAA or Conference rules," Petitti wrote.

Petitti said he was particularly concerned that Michigan's letter from Wednesday stated that the school had not yet had a chance to review "almost any of the evidence" provided to the university and the conference by NCAA investigators. The letter says that Michigan has had more than a week to review documents provided by the NCAA, and that at least three university officials had attended NCAA interviews where evidence of the alleged cheating scheme were revealed.

Michigan and Harbaugh's attorneys argued Wednesday that recent evidence of other schools engaging in schemes to learn the Wolverines' playcalling signs made it clear that the team did not maintain an exceptional competitive advantage through any of its staff's efforts. They also noted the commissioner could be setting a difficult precedent if he were going to use the sportsmanship policy to punish any program or coach who was widely accused of stealing signals.

Petitti wrote Friday that the Big Ten has not received any information about other schools using "impermissible advanced in-person scouting, let alone a scheme of the size and scale like the one at issue here."

He said the conference would take appropriate action if the Big Ten is made aware of any other schools engaged in impermissible behavior.

Petitti concluded his written case in the letter to Manuel by saying that he found it credible that the advantage Michigan gained from its sign-stealing scheme increased the risk that players on other teams could suffer injuries.

"Although the University attempted to downplay and disregard these safety concerns in its response, I am not willing to do so," he wrote.