Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net interest income	$ 106,207			$ 108,466			$ 315,159	$ 320,998
Provision for credit losses	1,760			2,899			40,526	7,180
Noninterest income	73,701			48,337			208,476	139,467
Noninterest expense	113,959			106,853			356,428	318,975
Income Before Income Taxes	64,189			47,051			126,681	134,310
Income taxes	9,749			6,016			17,873	17,796
Net Income	54,440	$ 32,150	$ 22,218	41,035	$ 42,140	$ 33,339	108,808	116,514
Selected Financial Information
Total assets	15,558,162			13,584,786			15,558,162	13,584,786	$ 13,497,877
Depreciation and amortization	10,344			10,462			30,000	29,585
General Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	104,738			106,806			310,517	315,708
Provision for credit losses	3,973			2,672			40,535	6,961
Noninterest income	54,422			29,576			149,649	83,297
Noninterest expense	98,384			93,103			308,189	273,211
Income Before Income Taxes	56,803			40,607			111,442	118,833
Income taxes	7,971			4,456			14,155	13,973
Net Income	48,832			36,151			97,287	104,860
Selected Financial Information
Total assets	15,255,359			13,221,723			15,255,359	13,221,723
Depreciation and amortization	10,081			10,254			29,297	28,985
Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest income	1,401			1,588			4,481	5,108
Provision for credit losses	(2,213)			227			(9)	219
Noninterest income	7,694			7,684			23,760	23,127
Noninterest expense	7,067			5,797			22,527	21,187
Income Before Income Taxes	4,241			3,248			5,723	6,829
Income taxes	1,009			812			1,380	1,703
Net Income	3,232			2,436			4,343	5,126
Selected Financial Information
Total assets	224,773			289,977			224,773	289,977
Depreciation and amortization	69			67			203	204
Insurance [Member]
Segment Reporting Information [Line Items]
Net interest income	68			72			161	182
Noninterest income	11,585			11,077			35,067	33,043
Noninterest expense	8,508			7,953			25,712	24,577
Income Before Income Taxes	3,145			3,196			9,516	8,648
Income taxes	769			748			2,338	2,120
Net Income	2,376			2,448			7,178	6,528
Selected Financial Information
Total assets	78,030			73,086			78,030	73,086
Depreciation and amortization	$ 194			$ 141			$ 500	$ 396