Loans - Acquired Loans (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Credit impaired acquired loans:
Outstanding principal balance	$ 53,214		$ 60,554
Recorded investment	39,326		46,174
Discount, net	13,888		14,380
Other acquired loans:
Outstanding principal balance	941,744		1,162,068
Recorded investment	935,046		1,150,938
Discount, net	6,524		10,968
Total acquired loans:
Outstanding principal balance	994,958		1,222,622
Deferred fees, net	(174)		(162)
Recorded investment	974,372		1,197,112
Discount, net	20,412		$ 25,348
Changes in the accretable yield for credit impaired acquired loans
Beginning balance	966	$ 685
Reclassifications from nonaccretable yield		480
Accretion	(38)	(63)
Balance at period end	$ 928	$ 1,102