Condensed Parent Company Financial Statements (Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Jun. 30, 2016	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities:
Net income		$ 54,608	$ 53,115	$ 50,041	$ 49,111	$ 35,512	$ 38,355	$ 43,831	$ 39,052	$ 206,875	$ 156,749	$ 151,398
Adjustments to reconcile net income to net cash provided by (used for) operating activities
Provision for credit losses		7,350	$ 9,571	$ 9,129	8,034	9,059	$ 8,322	$ 9,482	6,079	34,084	32,942	20,537
Losses on available-for-sale securities, net										(7,645)	(323)	504
Gain on early extinguishment of debt										(3,588)	0	0
Depreciation and amortization										53,148	41,010	37,792
Deferred income tax (benefit) expense										6,676	23,054	4,125
Stock-based compensation expense										9,303	9,656	7,754
Excess tax benefits from stock-based compensation arrangements										(951)	(744)	(444)
Increase in other assets										(43,614)	(151,132)	72,479
Increase in other liabilities										113,258	292	(38,902)
Net Cash Provided by Operating Activities										309,081	38,222	206,368
Investing Activities:
Net cash paid for acquisitions, net										(613,619)	(15,428)	228,946
Net Cash Used for Investing Activities										(2,492,665)	(1,641,553)	(1,837,592)
Financing Activities:
(Decrease) increase in subordinated notes, other borrowings and junior subordinated debt, net										(3,405)	44,415	(59,384)
Proceeds from the issuance of subordinated notes, net										0	0	139,090
Excess tax benefits from stock-based compensation arrangements										951	744	444
Proceeds from the issuance of common stock, net	$ 152,900									152,911	0	0
Net proceeds from issuance of Series D Preferred Stock										0	120,842	0
Issuance of common shares resulting from exercise of stock options, employee stock purchase plan and conversion of common stock warrants										15,828	16,119	10,453
Dividends paid										(38,568)	(29,888)	(24,933)
Common stock repurchases										(616)	(424)	(549)
Net Cash Provided by Financing Activities										2,177,834	1,648,419	1,598,067
Net (Decrease) Increase in Cash and Cash Equivalents										(5,750)	45,088	(33,157)
Cash and Cash Equivalents at Beginning of Period					275,795				230,707	275,795	230,707	263,864
Cash and Cash Equivalents at End of Period		270,045				275,795				270,045	275,795	230,707
Reportable Legal Entities | Parent Company
Operating Activities:
Net income										206,875	156,749	151,398
Adjustments to reconcile net income to net cash provided by (used for) operating activities
Provision for credit losses										0	(96)	945
Losses on available-for-sale securities, net										0	0	33
Gain on early extinguishment of debt										(4,305)	0	0
Depreciation and amortization										10,400	8,323	7,853
Deferred income tax (benefit) expense										(601)	(1,872)	2,753
Stock-based compensation expense										3,762	3,354	2,654
Excess tax benefits from stock-based compensation arrangements										(225)	(278)	(139)
Increase in other assets										(319)	(39,051)	(4,473)
Increase in other liabilities										9,618	21,840	7,114
Equity in undistributed net income of subsidiaries										(197,861)	(183,830)	(111,622)
Net Cash Provided by Operating Activities										27,344	(34,861)	56,516
Investing Activities:
Capital contributions to subsidiaries, net										(118,575)	(97,400)	(105,244)
Net cash paid for acquisitions, net										(61,308)	(51,060)	0
Other investing activity, net										(18,051)	(24,908)	(3,907)
Net Cash Used for Investing Activities										(197,934)	(173,368)	(109,151)
Financing Activities:
(Decrease) increase in subordinated notes, other borrowings and junior subordinated debt, net										(26,251)	66,888	(1,131)
Proceeds from the issuance of subordinated notes, net										0	0	139,090
Excess tax benefits from stock-based compensation arrangements										225	278	139
Proceeds from the issuance of common stock, net										152,911	0	0
Net proceeds from issuance of Series D Preferred Stock										0	120,842	0
Issuance of common shares resulting from exercise of stock options, employee stock purchase plan and conversion of common stock warrants										15,828	16,119	10,453
Dividends paid										(38,568)	(29,888)	(24,933)
Common stock repurchases										(616)	(424)	(549)
Net Cash Provided by Financing Activities										103,529	173,815	123,069
Net (Decrease) Increase in Cash and Cash Equivalents										(67,061)	(34,414)	70,434
Cash and Cash Equivalents at Beginning of Period					$ 116,889				$ 151,303	116,889	151,303	80,869
Cash and Cash Equivalents at End of Period		$ 49,828				$ 116,889				$ 49,828	$ 116,889	$ 151,303