Goodwill	12 Months Ended
Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill Goodwill was $1.13 billion and $287.4 million for the periods ended December 31, 2016 and 2015, respectively. Goodwill recorded is primarily attributable to the synergies and economies of scale expected from combining the operations of the Corporation and other acquisitions. The Corporation recorded goodwill in the amount of $846.7 million related to the merger with Talmer completed on August 31, 2016. During 2015, the Corporation acquired Lake Michigan and Monarch, which resulted in the recognition of goodwill for each transaction of $101.1 million and $5.3 million, respectively. Goodwill is subject to impairment testing annually as of October 31 and on an interim basis if events or changes in circumstances indicate assets might be impaired. Impairment exists when the carrying value of goodwill exceeds its fair value. At December 31, 2016, the Corporation had positive equity and the Corporation elected to perform a qualitative assessment to determine if it was more likely than not that the fair value exceeded its carrying value, including goodwill. The qualitative assessment indicated that it was more likely than not that the fair value exceeded its carrying value, resulting in no impairment.

Goodwill

Goodwill was $1.13 billion and $287.4 million for the periods ended December 31, 2016 and 2015, respectively. Goodwill recorded is primarily attributable to the synergies and economies of scale expected from combining the operations of the Corporation and other acquisitions. The Corporation recorded goodwill in the amount of $846.7 million related to the merger with Talmer completed on August 31, 2016. During 2015, the Corporation acquired Lake Michigan and Monarch, which resulted in the recognition of goodwill for each transaction of $101.1 million and $5.3 million, respectively.

Goodwill is subject to impairment testing annually as of October 31 and on an interim basis if events or changes in circumstances indicate assets might be impaired. Impairment exists when the carrying value of goodwill exceeds its fair value. At December 31, 2016, the Corporation had positive equity and the Corporation elected to perform a qualitative assessment to determine if it was more likely than not that the fair value exceeded its carrying value, including goodwill. The qualitative assessment indicated that it was more likely than not that the fair value exceeded its carrying value, resulting in no impairment.