Condensed Financial Information (Parent Company Only) - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed balance sheets:
Cash and cash equivalents	$ 782,023	$ 780,457
Investment in subsidiaries, at equity:
Other assets	81,705	78,074
Total assets	9,063,895	8,728,196
Subordinated debentures held by subsidiary trusts	82,477	82,477
Total liabilities	8,081,302	7,777,703
Stockholders’ equity	982,593	950,493	$ 908,924	$ 801,581
Total liabilities and stockholders’ equity	9,063,895	8,728,196
Parent Company
Condensed balance sheets:
Cash and cash equivalents	138,385	55,162
Investment in subsidiaries, at equity:
Equity method investments	932,034	977,221
Advances from subsidiaries, net	0	6,257
Other assets	35,349	39,668
Total assets	1,105,768	1,078,308
Other liabilities	18,004	25,338
Investments In Subsidiaries and Advances From Subsidiaries, Net	2,694	0
Long-term debt	20,000	20,000
Subordinated debentures held by subsidiary trusts	82,477	82,477
Total liabilities	123,175	127,815
Stockholders’ equity	982,593	950,493
Total liabilities and stockholders’ equity	1,105,768	1,078,308
Bank subsidiary
Investment in subsidiaries, at equity:
Equity method investments	932,034	975,236
Nonbank subsidiaries
Investment in subsidiaries, at equity:
Equity method investments	$ 0	$ 1,985