The NHL and NHLPA released a multi-page PDF explaining the ruling from the arbitrator, so here is the basic information you need to know.

added 2:16pm,

NEW YORK (March 11, 2016) – The National Hockey League released the following statement today regarding the decision in the appeal of Calgary Flames defenseman Dennis Wideman’s 20-game suspension:

“We are in receipt of Arbitrator James Oldham’s Opinion in the appeal of Dennis Wideman’s supplementary discipline suspension and reducing the suspension from 20 to 10 games. We strenuously disagree with the Arbitrator’s ruling and are reviewing the Opinion in detail to determine what next steps may be appropriate. We will have no further comment until we have completed our review. In light of and in response to Arbitrator Oldham’s Opinion, Mr. Wideman will be reinstated and will be eligible to participate in his team’s games, effective immediately.”