Goodwill and Other Intangible Assets (Details) - Core Deposit Intangibles - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-lived Intangible Assets [Roll Forward]
Balance at the beginning of the year, gross	$ 48,550	$ 47,970	$ 33,775
Balance at the beginning of the year, accumulated amortization	28,280	24,360	21,471
Balance at the beginning of the year, net	20,270	23,610	12,304
Additions	10,409	580	14,195
Amortization expense	(4,682)	(3,920)	(2,889)
Balance at the end of the year, gross	58,959	48,550	47,970
Balance at the end of the year, accumulated amortization	32,962	28,280	24,360
Balance at the end of the year, net	$ 25,997	$ 20,270	$ 23,610
Weighted-average remaining life (in years)	7 years 6 months 20 days	7 years 5 months 9 days	8 years
Minimum
Finite-lived Intangible Assets [Roll Forward]
Estimated useful lives (in years)	7 months	9 months 6 days	3 months 6 days
Maximum
Finite-lived Intangible Assets [Roll Forward]
Estimated useful lives (in years)	9 years 3 months	10 years	10 years 3 months 6 days