Loans and Allowance for Credit Losses for Loans - Internal Loan Classification Risk by Loan Portfolio Class by Origination Year (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 48,659,966		$ 46,917,200
Gross loan charge-offs
Total	32,573	$ 2,595
Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	437,316		1,633,478
Year two, fiscal year before current fiscal year	1,447,484		1,115,331
Year three, two years before current fiscal year	1,028,849		614,019
Year four, three years before current fiscal year	571,285		331,400
Year five, four years before current fiscal year	311,681		258,656
More than five years before current fiscal year	706,171		458,680
Revolving Loans Amortized Cost Basis	4,541,023		4,393,115
Revolving Loans Converted to Term Loans	137		151
Total	9,043,946		8,804,830
Gross loan charge-offs
Total	26,047	1,571
Commercial and industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	435,733		1,600,747
Year two, fiscal year before current fiscal year	1,418,804		1,089,386
Year three, two years before current fiscal year	1,021,874		590,406
Year four, three years before current fiscal year	549,408		322,564
Year five, four years before current fiscal year	304,137		250,031
More than five years before current fiscal year	628,117		386,085
Revolving Loans Amortized Cost Basis	4,450,850		4,307,163
Revolving Loans Converted to Term Loans	130		144
Total	8,809,053		8,546,526
Commercial and industrial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,573		31,557
Year two, fiscal year before current fiscal year	27,386		3,367
Year three, two years before current fiscal year	2,591		19,492
Year four, three years before current fiscal year	19,260		4,732
Year five, four years before current fiscal year	3,658		4,369
More than five years before current fiscal year	7,443		3,558
Revolving Loans Amortized Cost Basis	61,455		51,021
Revolving Loans Converted to Term Loans	7		7
Total	123,373		118,103
Commercial and industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	10		288
Year two, fiscal year before current fiscal year	517		1,734
Year three, two years before current fiscal year	2,832		4,121
Year four, three years before current fiscal year	2,617		1,412
Year five, four years before current fiscal year	1,203		4,256
More than five years before current fiscal year	6,904		4,879
Revolving Loans Amortized Cost Basis	25,847		31,698
Revolving Loans Converted to Term Loans	0		0
Total	39,930		48,388
Commercial and industrial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0		886
Year two, fiscal year before current fiscal year	777		20,844
Year three, two years before current fiscal year	1,552		0
Year four, three years before current fiscal year	0		2,692
Year five, four years before current fiscal year	2,683		0
More than five years before current fiscal year	63,707		64,158
Revolving Loans Amortized Cost Basis	2,871		3,233
Revolving Loans Converted to Term Loans	0		0
Total	71,590		91,813
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	30,777,078		29,432,868
Gross loan charge-offs
Total	5,698	$ 173
Commercial real estate | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,634,473		6,923,489
Year two, fiscal year before current fiscal year	6,829,589		5,250,609
Year three, two years before current fiscal year	5,283,268		3,339,684
Year four, three years before current fiscal year	3,381,426		2,752,292
Year five, four years before current fiscal year	2,626,510		1,657,775
More than five years before current fiscal year	6,787,666		5,336,045
Revolving Loans Amortized Cost Basis	504,772		468,635
Revolving Loans Converted to Term Loans	3,407		3,504
Total	27,051,111		25,732,033
Commercial real estate | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,607,961		6,815,115
Year two, fiscal year before current fiscal year	6,740,087		5,168,127
Year three, two years before current fiscal year	5,201,027		3,246,885
Year four, three years before current fiscal year	3,287,689		2,672,223
Year five, four years before current fiscal year	2,520,271		1,536,327
More than five years before current fiscal year	6,316,475		5,027,128
Revolving Loans Amortized Cost Basis	490,136		452,461
Revolving Loans Converted to Term Loans	3,407		3,504
Total	26,167,053		24,921,770
Commercial real estate | Commercial real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	26,512		93,286
Year two, fiscal year before current fiscal year	55,889		48,007
Year three, two years before current fiscal year	46,317		60,169
Year four, three years before current fiscal year	63,647		45,447
Year five, four years before current fiscal year	71,474		62,111
More than five years before current fiscal year	251,353		125,414
Revolving Loans Amortized Cost Basis	6,720		8,188
Revolving Loans Converted to Term Loans	0		0
Total	521,912		442,622
Commercial real estate | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0		15,088
Year two, fiscal year before current fiscal year	33,613		34,475
Year three, two years before current fiscal year	35,924		32,630
Year four, three years before current fiscal year	30,090		34,622
Year five, four years before current fiscal year	34,765		59,337
More than five years before current fiscal year	219,838		183,341
Revolving Loans Amortized Cost Basis	7,916		7,986
Revolving Loans Converted to Term Loans	0		0
Total	362,146		367,479
Commercial real estate | Commercial real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year			0
Year two, fiscal year before current fiscal year			0
Year three, two years before current fiscal year			0
Year four, three years before current fiscal year			0
Year five, four years before current fiscal year			0
More than five years before current fiscal year			162
Revolving Loans Amortized Cost Basis			0
Revolving Loans Converted to Term Loans			0
Total			162
Commercial real estate | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	120,729		955,349
Year two, fiscal year before current fiscal year	936,843		524,647
Year three, two years before current fiscal year	428,172		61,131
Year four, three years before current fiscal year	82,032		23,819
Year five, four years before current fiscal year	16,466		8,676
More than five years before current fiscal year	54,463		51,941
Revolving Loans Amortized Cost Basis	2,087,262		2,075,272
Revolving Loans Converted to Term Loans	0		0
Total	3,725,967		3,700,835
Commercial real estate | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	120,282		942,380
Year two, fiscal year before current fiscal year	928,489		512,046
Year three, two years before current fiscal year	415,212		61,131
Year four, three years before current fiscal year	70,371		22,845
Year five, four years before current fiscal year	15,502		8,676
More than five years before current fiscal year	36,863		20,599
Revolving Loans Amortized Cost Basis	2,079,911		2,040,866
Revolving Loans Converted to Term Loans	0		0
Total	3,666,630		3,608,543
Commercial real estate | Construction | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year			0
Year two, fiscal year before current fiscal year			0
Year three, two years before current fiscal year			0
Year four, three years before current fiscal year			0
Year five, four years before current fiscal year			0
More than five years before current fiscal year			0
Revolving Loans Amortized Cost Basis			14,268
Revolving Loans Converted to Term Loans			0
Total			14,268
Commercial real estate | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0		12,969
Year two, fiscal year before current fiscal year	13		12,601
Year three, two years before current fiscal year	12,290		0
Year four, three years before current fiscal year	0		974
Year five, four years before current fiscal year	964		0
More than five years before current fiscal year	17,600		17,599
Revolving Loans Amortized Cost Basis	7,351		20,138
Revolving Loans Converted to Term Loans	0		0
Total	38,218		64,281
Commercial real estate | Construction | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	447		0
Year two, fiscal year before current fiscal year	8,341		0
Year three, two years before current fiscal year	670		0
Year four, three years before current fiscal year	11,661		0
Year five, four years before current fiscal year	0		0
More than five years before current fiscal year	0		13,743
Revolving Loans Amortized Cost Basis	0		0
Revolving Loans Converted to Term Loans	0		0
Total	21,119		$ 13,743
Commercial and Industrial and Commercial Real Estate
Gross loan charge-offs
2023	0
2022	6,035
2021	20,286
2020	123
2019	72
Prior to 2019	1,636
Revolving Loans Amortized Cost Basis	3,593
Revolving Loans Converted to Term Loans	0
Total	$ 31,745