Loans and Allowance for Credit Losses for Loans - Internal Loan Classification Risk by Loan Portfolio Class by Origination Year (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 34,153,657	$ 32,217,112
Commercial and industrial *
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,575,480	3,064,630
Year two, fiscal year before current fiscal year	749,183	624,427
Year three, two years before current fiscal year	470,111	570,901
Year four, three years before current fiscal year	383,968	240,525
Year five, four years before current fiscal year	162,744	179,522
More than five years before current fiscal year	415,369	434,485
Revolving Loans Amortized Cost Basis	2,090,300	1,746,355
Revolving Loans Converted to Term Loans	396	863
Total	5,847,551	6,861,708
Commercial and industrial * | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,563,050	3,058,596
Year two, fiscal year before current fiscal year	743,165	605,112
Year three, two years before current fiscal year	461,022	556,284
Year four, three years before current fiscal year	362,748	212,215
Year five, four years before current fiscal year	143,753	162,483
More than five years before current fiscal year	337,713	337,484
Revolving Loans Amortized Cost Basis	1,968,513	1,677,559
Revolving Loans Converted to Term Loans	247	350
Total	5,580,211	6,610,083
Commercial and industrial * | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	4,182	819
Year two, fiscal year before current fiscal year	1,195	10,236
Year three, two years before current fiscal year	3,217	2,135
Year four, three years before current fiscal year	14,143	9,502
Year five, four years before current fiscal year	1,726	10,228
More than five years before current fiscal year	9,869	14,165
Revolving Loans Amortized Cost Basis	102,145	49,883
Revolving Loans Converted to Term Loans	40	51
Total	136,517	97,019
Commercial and industrial * | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	8,248	5,215
Year two, fiscal year before current fiscal year	4,823	3,876
Year three, two years before current fiscal year	3,139	12,481
Year four, three years before current fiscal year	7,077	1,798
Year five, four years before current fiscal year	910	4,215
More than five years before current fiscal year	408	12,965
Revolving Loans Amortized Cost Basis	19,642	18,913
Revolving Loans Converted to Term Loans	109	462
Total	44,356	59,925
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	5,203
Year three, two years before current fiscal year	2,733	1
Year four, three years before current fiscal year	0	17,010
Year five, four years before current fiscal year	16,355	2,596
More than five years before current fiscal year	67,379	69,871
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	86,467	94,681
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	20,790,066	18,470,823
Commercial real estate | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	4,526,352	3,165,678
Year two, fiscal year before current fiscal year	3,067,814	3,137,328
Year three, two years before current fiscal year	2,778,520	2,305,380
Year four, three years before current fiscal year	1,820,340	1,875,959
Year five, four years before current fiscal year	1,611,334	1,876,523
More than five years before current fiscal year	4,869,778	4,145,217
Revolving Loans Amortized Cost Basis	247,968	203,381
Revolving Loans Converted to Term Loans	13,380	15,532
Total	18,935,486	16,724,998
Commercial real estate | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	4,517,917	3,096,549
Year two, fiscal year before current fiscal year	2,983,140	3,052,076
Year three, two years before current fiscal year	2,702,580	2,230,047
Year four, three years before current fiscal year	1,734,922	1,767,528
Year five, four years before current fiscal year	1,474,770	1,798,137
More than five years before current fiscal year	4,557,011	3,916,990
Revolving Loans Amortized Cost Basis	195,851	199,145
Revolving Loans Converted to Term Loans	13,380	15,532
Total	18,179,571	16,076,004
Commercial real estate | Commercial real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	7,700	50,193
Year two, fiscal year before current fiscal year	50,019	68,203
Year three, two years before current fiscal year	46,911	44,336
Year four, three years before current fiscal year	44,187	48,813
Year five, four years before current fiscal year	65,623	66,845
More than five years before current fiscal year	143,540	109,295
Revolving Loans Amortized Cost Basis	50,168	1,705
Revolving Loans Converted to Term Loans	0	0
Total	408,148	389,390
Commercial real estate | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	735	18,936
Year two, fiscal year before current fiscal year	34,655	17,049
Year three, two years before current fiscal year	29,029	30,997
Year four, three years before current fiscal year	41,231	59,618
Year five, four years before current fiscal year	70,941	11,541
More than five years before current fiscal year	169,041	118,725
Revolving Loans Amortized Cost Basis	1,949	2,531
Revolving Loans Converted to Term Loans	0	0
Total	347,581	259,397
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	186	207
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	186	207
Commercial real estate | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	278,427	145,246
Year two, fiscal year before current fiscal year	98,628	121,869
Year three, two years before current fiscal year	49,570	111,420
Year four, three years before current fiscal year	33,027	18,125
Year five, four years before current fiscal year	6,061	57,984
More than five years before current fiscal year	46,261	37,823
Revolving Loans Amortized Cost Basis	1,342,606	1,253,358
Revolving Loans Converted to Term Loans	0	0
Total	1,854,580	1,745,825
Commercial real estate | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	274,097	145,246
Year two, fiscal year before current fiscal year	98,609	120,800
Year three, two years before current fiscal year	48,555	111,174
Year four, three years before current fiscal year	32,781	15,497
Year five, four years before current fiscal year	6,061	47,971
More than five years before current fiscal year	28,419	20,029
Revolving Loans Amortized Cost Basis	1,313,555	1,199,034
Revolving Loans Converted to Term Loans	0	0
Total	1,802,077	1,659,751
Commercial real estate | Construction | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	4,131	0
Year two, fiscal year before current fiscal year	0	1,043
Year three, two years before current fiscal year	1,009	0
Year four, three years before current fiscal year	0	0
Year five, four years before current fiscal year	0	9,996
More than five years before current fiscal year	0	17,414
Revolving Loans Amortized Cost Basis	18,449	47,311
Revolving Loans Converted to Term Loans	0	0
Total	23,589	75,764
Commercial real estate | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	199	0
Year two, fiscal year before current fiscal year	19	26
Year three, two years before current fiscal year	6	246
Year four, three years before current fiscal year	246	2,628
Year five, four years before current fiscal year	0	17
More than five years before current fiscal year	17,842	380
Revolving Loans Amortized Cost Basis	10,602	7,013
Revolving Loans Converted to Term Loans	0	0
Total	$ 28,914	$ 10,310