Significant Accounting Policies - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of cash flows specific transaction amounts [Abstract]
Income taxes paid		$ 24,836	$ 16,321	$ 13,710
Interest expense paid on deposits and borrowings		24,312	20,733	22,268
Noncash transfers from loans to foreclosed properties	[1]	23,965	$ 32,782	39,778
Transfer of long-term FHLB advances to short-term		$ 500,009		$ 6,644

[1] Includes transfers from covered loans to foreclosed properties.