Fees and Commission Revenue Fees and Commissions (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		$ 702,201	$ 643,176	$ 681,014
Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		702,201	643,176
Fees and commissions revenue not from contracts with customers	[1]	263,146	209,384
Fees and commissions revenue from contracts with customers	[2]	439,055	433,792
Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		159,826	108,323	131,601
Fees and commissions revenue not from contracts with customers	[1]	116,177	73,291
Fees and commissions revenue from contracts with customers	[2]	43,649	35,032
Trading Revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		88,558	28,077
Fees and commissions revenue not from contracts with customers	[1]	88,558	28,077
Fees and commissions revenue from contracts with customers	[2]	0	0
Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		18,941	38,834
Fees and commissions revenue not from contracts with customers	[1]	18,941	38,834
Fees and commissions revenue from contracts with customers	[2]	0	0
Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		16,136	17,952
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	16,136	17,952
Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		13,861	4,198
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	13,861	4,198
Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		22,330	19,262
Fees and commissions revenue not from contracts with customers	[1]	8,678	6,380
Fees and commissions revenue from contracts with customers	[2]	13,652	12,882
Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		87,216	84,025	119,988
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	87,216	84,025
TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		77,324	76,221
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	77,324	76,221
Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		8,786	7,804
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	8,786	7,804
Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		1,106	0
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	1,106	0
Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		177,025	184,703	162,889
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	177,025	184,703
Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		81,763	96,839
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	81,763	96,839
Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		24,635	22,292
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	24,635	22,292
Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		44,352	44,476
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	44,352	44,476
Investment management services and other [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		26,275	21,096
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	26,275	21,096
Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		112,485	112,153	112,079
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	112,485	112,153
Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		47,905	47,272
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	47,905	47,272
Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		35,356	36,536
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	35,356	36,536
Check card fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		22,030	21,306
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	22,030	21,306
Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		7,194	7,039
Fees and commissions revenue not from contracts with customers	[1]	0	0
Fees and commissions revenue from contracts with customers	[2]	7,194	7,039
Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		107,541	97,787	104,719
Fees and commissions revenue not from contracts with customers	[1]	107,541	97,787
Fees and commissions revenue from contracts with customers	[2]	0	0
Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		42,720	31,690
Fees and commissions revenue not from contracts with customers	[1]	42,720	31,690
Fees and commissions revenue from contracts with customers	[2]	0	0
Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		64,821	66,097
Fees and commissions revenue not from contracts with customers	[1]	64,821	66,097
Fees and commissions revenue from contracts with customers	[2]	0	0
Other revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		58,108	56,185	$ 49,738
Fees and commissions revenue not from contracts with customers	[1]	39,428	38,306
Fees and commissions revenue from contracts with customers	[2]	18,680	17,879
Operating Segments [Member] | Commercial [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		168,667	161,949
Operating Segments [Member] | Commercial [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		18,558	15,376
Operating Segments [Member] | Commercial [Member] | Trading Revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		8,422	7,748
Operating Segments [Member] | Commercial [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		10,136	7,628
Operating Segments [Member] | Commercial [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		83,158	79,946
Operating Segments [Member] | Commercial [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		73,479	72,280
Operating Segments [Member] | Commercial [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		8,607	7,666
Operating Segments [Member] | Commercial [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		1,072	0
Operating Segments [Member] | Commercial [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Investment management services and other [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		43,387	42,583
Operating Segments [Member] | Commercial [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		42,251	41,931
Operating Segments [Member] | Commercial [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		313	370
Operating Segments [Member] | Commercial [Member] | Check card fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		823	282
Operating Segments [Member] | Commercial [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Commercial [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		23,564	24,044
Operating Segments [Member] | Consumer [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		187,996	178,174
Operating Segments [Member] | Consumer [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Trading Revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		3,980	4,076
Operating Segments [Member] | Consumer [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		3,924	4,017
Operating Segments [Member] | Consumer [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		56	59
Operating Segments [Member] | Consumer [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Investment management services and other [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Consumer [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		64,867	65,210
Operating Segments [Member] | Consumer [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		1,713	1,445
Operating Segments [Member] | Consumer [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		35,134	36,177
Operating Segments [Member] | Consumer [Member] | Check card fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		21,865	20,967
Operating Segments [Member] | Consumer [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		6,155	6,621
Operating Segments [Member] | Consumer [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		109,416	99,670
Operating Segments [Member] | Consumer [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		42,724	31,690
Operating Segments [Member] | Consumer [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		66,692	67,980
Operating Segments [Member] | Consumer [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		9,733	9,218
Operating Segments [Member] | Wealth Management [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		341,333	296,465
Operating Segments [Member] | Wealth Management [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		136,801	86,253
Operating Segments [Member] | Wealth Management [Member] | Trading Revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		88,558	28,077
Operating Segments [Member] | Wealth Management [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		9,667	27,512
Operating Segments [Member] | Wealth Management [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		16,251	19,030
Operating Segments [Member] | Wealth Management [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		10,131	0
Operating Segments [Member] | Wealth Management [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		12,194	11,634
Operating Segments [Member] | Wealth Management [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		(50)	(82)
Operating Segments [Member] | Wealth Management [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		(82)	(82)
Operating Segments [Member] | Wealth Management [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Wealth Management [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		32	0
Operating Segments [Member] | Wealth Management [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		175,475	183,260
Operating Segments [Member] | Wealth Management [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		81,763	96,839
Operating Segments [Member] | Wealth Management [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		24,635	22,292
Operating Segments [Member] | Wealth Management [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		44,352	44,400
Operating Segments [Member] | Wealth Management [Member] | Investment management services and other [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		24,725	19,729
Operating Segments [Member] | Wealth Management [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		2,443	2,527
Operating Segments [Member] | Wealth Management [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		2,137	2,331
Operating Segments [Member] | Wealth Management [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		138	134
Operating Segments [Member] | Wealth Management [Member] | Check card fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Wealth Management [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		168	62
Operating Segments [Member] | Wealth Management [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Wealth Management [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Wealth Management [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Operating Segments [Member] | Wealth Management [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		26,664	24,507
Funds Management and Other [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		4,205	6,588
Funds Management and Other [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		4,467	6,694
Funds Management and Other [Member] | Trading Revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Funds Management and Other [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		852	3,574
Funds Management and Other [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		(115)	(1,078)
Funds Management and Other [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		3,730	4,198
Funds Management and Other [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Funds Management and Other [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		128	85
Funds Management and Other [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		3	6
Funds Management and Other [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		123	79
Funds Management and Other [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		2	0
Funds Management and Other [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		1,550	1,443
Funds Management and Other [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Funds Management and Other [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	0
Funds Management and Other [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		0	76
Funds Management and Other [Member] | Investment management services and other [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		1,550	1,367
Funds Management and Other [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		1,788	1,833
Funds Management and Other [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		1,804	1,565
Funds Management and Other [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		(229)	(145)
Funds Management and Other [Member] | Check card fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		165	339
Funds Management and Other [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		48	74
Funds Management and Other [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		(1,875)	(1,883)
Funds Management and Other [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		(4)	0
Funds Management and Other [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		(1,871)	(1,883)
Funds Management and Other [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Fess and commissions revenue		$ (1,853)	$ (1,584)

[1] Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.

[2] In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.