Goodwill and Intangible Assets, Summary of Core Deposit and Other Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of core deposit intangibles and other intangibles
Amortization of other intangible assets		$ 2,093	$ 3,094	$ 3,747
Core Deposit Intangibles
Summary of core deposit intangibles and other intangibles
Gross carrying amount		4,385	19,545	36,230
Accumulated amortization		(4,273)	(19,152)	(34,433)
Total Estimated Amortization Expense		112	393	1,797
Amortization of other intangible assets		281	1,404	2,868
Other Intangibles
Summary of core deposit intangibles and other intangibles
Gross carrying amount		32,410	31,398	19,283
Accumulated amortization		(17,145)	(15,333)	(13,643)
Total Estimated Amortization Expense		15,265	16,065	5,640
Additions during the period	$ 1,000	1,012	12,115	0
Amortization of other intangible assets		$ 1,812	$ 1,690	$ 879