Other Intangible Assets (Activity for Capitalized MSRs) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Intangible Assets [Roll Forward]
Total other intangible assets, Balance at beginning of year		$ 33,080
Amortization		(8,244)	$ (3,545)	$ (3,492)
Total other intangible assets, Balance at end of year		38,104	33,080
Valuation Allowance for Impairment of Recognized Servicing Assets, Balance	[1]	0	200	0
Mortgage servicing rights [Member]
Other Intangible Assets [Roll Forward]
Total other intangible assets, Balance at beginning of year		12,217	3,423	3,478
Acquired through acquisitions		1,284	9,235
Additions		1,476	1,075	1,528
Amortization		(4,055)	(1,316)	(1,583)
Change in valuation allowance attributable to mortage servicing assets		200	(200)	0
Total other intangible assets, Balance at end of year		11,122	12,217	3,423
Mortgage servicing rights [Member] | Monarch Community Bancorp [Member]
Other Intangible Assets [Roll Forward]
Additions		$ 1,300
Mortgage servicing rights [Member] | Northwestern Bancorp [Member]
Other Intangible Assets [Roll Forward]
Additions			$ 9,200
Mortgage servicing rights [Member] | OAK [Member]
Other Intangible Assets [Roll Forward]
Acquired through acquisitions				$ 0

[1] MSRs are stratified into servicing assets originated by the Corporation and those acquired in acquisitions of other institutions and further stratified into relatively homogeneous pools based on products with similar characteristics. The MSR impairment valuation allowance recorded at December 31, 2014 related to impairment within certain pools attributable to the Corporation's servicing portfolio that was acquired in the Northwestern transaction.