Investment Securities - Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Debt Securities Held to Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	$ 3,828,984	$ 2,668,697
Gross Unrealized Gains	2,105	25,980
Gross Unrealized Losses	(501,619)	(34,072)
Fair Value	3,329,470	2,660,605
Held-to-maturity, allowance for credit loss	1,646	1,165	$ 1,428	$ 0
Net Carrying Value	3,827,338	2,667,532
U.S. Treasury securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	66,911	67,558
Gross Unrealized Gains	0	4,103
Gross Unrealized Losses	(1,022)	0
Fair Value	65,889	71,661
Held-to-maturity, allowance for credit loss	0	0
Net Carrying Value	66,911	67,558
U.S. government agency securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	260,392	6,265
Gross Unrealized Gains	0	113
Gross Unrealized Losses	(47,680)	0
Fair Value	212,712	6,378
Held-to-maturity, allowance for credit loss	0	0
Net Carrying Value	260,392	6,265
Obligations of states and state agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	99,238	141,015
Gross Unrealized Gains	305	3,065
Gross Unrealized Losses	(3,869)	(312)
Fair Value	95,674	143,768
Held-to-maturity, allowance for credit loss	252	267
Net Carrying Value	98,986	140,748
Municipal bonds
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	381,060	196,947
Gross Unrealized Gains	76	3,536
Gross Unrealized Losses	(23,615)	(87)
Fair Value	357,521	200,396
Held-to-maturity, allowance for credit loss	41	15
Net Carrying Value	381,019	196,932
Obligations of states and political subdivisions
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	480,298	337,962
Gross Unrealized Gains	381	6,601
Gross Unrealized Losses	(27,484)	(399)
Fair Value	453,195	344,164
Held-to-maturity, allowance for credit loss	293	282
Net Carrying Value	480,005	337,680
Residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	2,909,106	2,166,142
Gross Unrealized Gains	1,723	14,599
Gross Unrealized Losses	(415,032)	(28,440)
Fair Value	2,495,797	2,152,301
Held-to-maturity, allowance for credit loss	0	0
Net Carrying Value	2,909,106	2,166,142
Trust preferred securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	37,043	37,020
Gross Unrealized Gains	1	5
Gross Unrealized Losses	(5,938)	(5,109)
Fair Value	31,106	31,916
Held-to-maturity, allowance for credit loss	888	531
Net Carrying Value	36,155	36,489
Corporate and other debt securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	75,234	53,750
Gross Unrealized Gains	0	559
Gross Unrealized Losses	(4,463)	(124)
Fair Value	70,771	54,185
Held-to-maturity, allowance for credit loss	465	352
Net Carrying Value	$ 74,769	$ 53,398