Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net interest income	$ 103,912	$ 97,564	$ 303,506	$ 288,681
Provision for loan losses, net	2,019	4,975	3,533	11,730
Noninterest income	44,480	44,716	140,703	132,219
Noninterest expense	103,086	97,908	327,218	307,031
Income Before Income Taxes	43,287	39,397	113,458	102,139
Income taxes	8,708	8,415	23,596	22,651
Net Income	34,579	30,982	89,862	79,488
Selected Financial Information
Total assets	13,884,655	13,161,538	13,884,655	13,161,538	$ 13,352,333
Depreciation and amortization	10,052	9,504	28,781	27,183
General Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	103,408	97,395	302,613	287,950
Provision for loan losses, net	2,019	4,975	3,533	11,730
Noninterest income	26,570	27,207	88,830	81,230
Noninterest expense	88,814	84,358	284,420	267,063
Income Before Income Taxes	39,145	35,269	103,490	90,387
Income taxes	7,130	6,844	19,772	18,168
Net Income	32,015	28,425	83,718	72,219
Selected Financial Information
Total assets	13,811,335	13,086,991	13,811,335	13,086,991
Depreciation and amortization	9,863	9,274	28,196	26,483
Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest income	434	119	718	571
Noninterest income	7,512	7,434	22,513	22,681
Noninterest expense	6,791	6,216	20,361	18,200
Income Before Income Taxes	1,155	1,337	2,870	5,052
Income taxes	441	512	1,098	1,933
Net Income	714	825	1,772	3,119
Selected Financial Information
Total assets	6,635	7,626	6,635	7,626
Depreciation and amortization	30	44	104	131
Insurance [Member]
Segment Reporting Information [Line Items]
Net interest income	70	50	175	160
Noninterest income	10,398	10,075	29,360	28,308
Noninterest expense	7,481	7,334	22,437	21,768
Income Before Income Taxes	2,987	2,791	7,098	6,700
Income taxes	1,137	1,059	2,726	2,550
Net Income	1,850	1,732	4,372	4,150
Selected Financial Information
Total assets	66,685	66,921	66,685	66,921
Depreciation and amortization	$ 159	$ 186	$ 481	$ 569