Loans and Allowance for Credit Losses for Loans - Internal Loan Classification Risk by Loan Portfolio Class by Origination Year (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 35,364,405	$ 34,153,657
Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	337,285	1,575,480
Year two, fiscal year before current fiscal year	1,231,144	749,183
Year three, two years before current fiscal year	711,939	470,111
Year four, three years before current fiscal year	423,750	383,968
Year five, four years before current fiscal year	341,726	162,744
More than five years before current fiscal year	542,481	415,369
Revolving Loans Amortized Cost Basis	2,202,736	2,090,300
Revolving Loans Converted to Term Loans	329	396
Total	5,791,390	5,847,551
Commercial and industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	337,060	1,563,050
Year two, fiscal year before current fiscal year	1,224,531	743,165
Year three, two years before current fiscal year	705,495	461,022
Year four, three years before current fiscal year	414,559	362,748
Year five, four years before current fiscal year	327,590	143,753
More than five years before current fiscal year	443,359	337,713
Revolving Loans Amortized Cost Basis	2,094,405	1,968,513
Revolving Loans Converted to Term Loans	208	247
Total	5,547,207	5,580,211
Commercial and industrial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	197	4,182
Year two, fiscal year before current fiscal year	4,469	1,195
Year three, two years before current fiscal year	716	3,217
Year four, three years before current fiscal year	3,087	14,143
Year five, four years before current fiscal year	13,566	1,726
More than five years before current fiscal year	9,848	9,869
Revolving Loans Amortized Cost Basis	97,834	102,145
Revolving Loans Converted to Term Loans	11	40
Total	129,728	136,517
Commercial and industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	28	8,248
Year two, fiscal year before current fiscal year	2,144	4,823
Year three, two years before current fiscal year	5,728	3,139
Year four, three years before current fiscal year	3,387	7,077
Year five, four years before current fiscal year	570	910
More than five years before current fiscal year	6,286	408
Revolving Loans Amortized Cost Basis	10,497	19,642
Revolving Loans Converted to Term Loans	110	109
Total	28,750	44,356
Commercial and industrial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	0
Year two, fiscal year before current fiscal year	0	0
Year three, two years before current fiscal year	0	2,733
Year four, three years before current fiscal year	2,717	0
Year five, four years before current fiscal year	0	16,355
More than five years before current fiscal year	82,988	67,379
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	85,705	86,467
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	21,937,744	20,790,066
Commercial real estate | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,304,920	4,526,352
Year two, fiscal year before current fiscal year	4,538,052	3,067,814
Year three, two years before current fiscal year	3,184,198	2,778,520
Year four, three years before current fiscal year	2,633,999	1,820,340
Year five, four years before current fiscal year	1,781,081	1,611,334
More than five years before current fiscal year	6,086,295	4,869,778
Revolving Loans Amortized Cost Basis	221,371	247,968
Revolving Loans Converted to Term Loans	13,286	13,380
Total	19,763,202	18,935,486
Commercial real estate | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,301,030	4,517,917
Year two, fiscal year before current fiscal year	4,505,671	2,983,140
Year three, two years before current fiscal year	3,074,999	2,702,580
Year four, three years before current fiscal year	2,564,818	1,734,922
Year five, four years before current fiscal year	1,654,197	1,474,770
More than five years before current fiscal year	5,685,062	4,557,011
Revolving Loans Amortized Cost Basis	203,527	195,851
Revolving Loans Converted to Term Loans	13,286	13,380
Total	19,002,590	18,179,571
Commercial real estate | Commercial real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	3,890	7,700
Year two, fiscal year before current fiscal year	22,188	50,019
Year three, two years before current fiscal year	69,992	46,911
Year four, three years before current fiscal year	32,837	44,187
Year five, four years before current fiscal year	84,259	65,623
More than five years before current fiscal year	176,080	143,540
Revolving Loans Amortized Cost Basis	9,684	50,168
Revolving Loans Converted to Term Loans	0	0
Total	398,930	408,148
Commercial real estate | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	735
Year two, fiscal year before current fiscal year	10,193	34,655
Year three, two years before current fiscal year	39,207	29,029
Year four, three years before current fiscal year	36,344	41,231
Year five, four years before current fiscal year	42,625	70,941
More than five years before current fiscal year	224,972	169,041
Revolving Loans Amortized Cost Basis	8,160	1,949
Revolving Loans Converted to Term Loans	0	0
Total	361,501	347,581
Commercial real estate | Commercial real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	0
Year two, fiscal year before current fiscal year	0	0
Year three, two years before current fiscal year	0	0
Year four, three years before current fiscal year	0	0
Year five, four years before current fiscal year	0	0
More than five years before current fiscal year	181	186
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	181	186
Commercial real estate | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	31,645	278,427
Year two, fiscal year before current fiscal year	313,251	98,628
Year three, two years before current fiscal year	88,262	49,570
Year four, three years before current fiscal year	45,546	33,027
Year five, four years before current fiscal year	13,381	6,061
More than five years before current fiscal year	35,559	46,261
Revolving Loans Amortized Cost Basis	1,646,898	1,342,606
Revolving Loans Converted to Term Loans	0	0
Total	2,174,542	1,854,580
Commercial real estate | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	31,645	274,097
Year two, fiscal year before current fiscal year	313,251	98,609
Year three, two years before current fiscal year	88,262	48,555
Year four, three years before current fiscal year	44,544	32,781
Year five, four years before current fiscal year	13,381	6,061
More than five years before current fiscal year	17,718	28,419
Revolving Loans Amortized Cost Basis	1,623,723	1,313,555
Revolving Loans Converted to Term Loans	0	0
Total	2,132,524	1,802,077
Commercial real estate | Construction | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	4,131
Year two, fiscal year before current fiscal year	0	0
Year three, two years before current fiscal year	0	1,009
Year four, three years before current fiscal year	1,001	0
Year five, four years before current fiscal year	0	0
More than five years before current fiscal year	0	0
Revolving Loans Amortized Cost Basis	21,467	18,449
Revolving Loans Converted to Term Loans	0	0
Total	22,468	23,589
Commercial real estate | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	199
Year two, fiscal year before current fiscal year	0	19
Year three, two years before current fiscal year	0	6
Year four, three years before current fiscal year	1	246
Year five, four years before current fiscal year	0	0
More than five years before current fiscal year	17,841	17,842
Revolving Loans Amortized Cost Basis	1,708	10,602
Revolving Loans Converted to Term Loans	0	0
Total	$ 19,550	$ 28,914