Goodwill, Core Deposit Premium and Other Intangible Assets (Changes in capitalized mortgage and commercial servicing rights) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Servicing Asset at Fair Value, Amount [Roll Forward]
Valuation allowance on commercial servicing rights	$ 5	$ 0
Mortgage servicing rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	32,088	30,314
Originations	2,132	2,395
Amortization	(2,261)	(2,259)
Balance at end of period	31,959	30,450
Fair value of servicing rights	$ 47,564	$ 45,210	$ 45,200
Servicing rights, net to servicing portfolio (as a percent)	0.74%	0.74%
Commercial servicing rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	$ 3,690	$ 4,611
Purchased commercial servicing rights	0	190
Originations	93	195
Amortization	(306)	(536)
Valuation allowance on commercial servicing rights	5	0
Balance at end of period	3,482	4,460
Fair value of servicing rights	$ 4,040	$ 4,899
Servicing rights, net to servicing portfolio (as a percent)	2.17%	2.35%