Financial Derivatives - Schedule of Derivative Instruments in Statement of Financial Position (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Notional Disclosures [Abstract]
Notional Amount	$ 17,547,367	$ 15,447,553
Asset
Asset	19,139	17,468
Collateral (held)/pledged	0	(1,345)
Net amount	19,139	16,123
(Liability)
(Liability)	(34,248)	(29,892)
Collateral (held)/pledged	194,519	212,263
Financial derivatives	160,271	182,371
Designated as hedge | Fair value hedges: | Pay fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	6,238,438	5,463,303
Asset
Asset	11,554	10,157
(Liability)
(Liability)	$ (583)	$ (2,585)
Weighted- Average Pay Rate	2.06%	2.26%
Weighted- Average Receive Rate	0.13%	0.21%
Weighted- Average Remaining Term (in years)	11 years 7 months 20 days	11 years 11 months 12 days
Designated as hedge | Fair value hedges: | Receive fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	$ 5,884,529	$ 2,611,029
Asset
Asset	15	2
(Liability)
(Liability)	$ (8,383)	$ (8,755)
Weighted- Average Pay Rate	0.17%	0.32%
Weighted- Average Receive Rate	0.88%	1.61%
Weighted- Average Remaining Term (in years)	2 years 3 months 7 days	2 years 1 month 6 days
Designated as hedge | Fair value hedges: | Receive fixed callable
Notional Disclosures [Abstract]
Notional Amount	$ 1,571,577	$ 343,500
Asset
Asset	103	3,108
(Liability)
(Liability)	$ (17,612)	$ (4)
Weighted- Average Pay Rate	0.01%	0.16%
Weighted- Average Receive Rate	0.80%	1.78%
Weighted- Average Remaining Term (in years)	4 years 2 months 1 day	3 years 1 month 28 days
Designated as hedge | Cash flow hedges: | Pay fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	$ 570,000	$ 472,000
Asset
Asset	6,905	2,584
(Liability)
(Liability)	$ (2,763)	$ (8,771)
Weighted- Average Pay Rate	1.93%	2.04%
Weighted- Average Receive Rate	0.49%	0.57%
Weighted- Average Remaining Term (in years)	5 years 8 months 19 days	6 years 14 days
No hedge designation
Asset
Credit valuation adjustment	$ 0	$ (1)
(Liability)
Credit valuation adjustment	14	35
No hedge designation | Pay fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	229,062	339,090
Asset
Asset	0	0
(Liability)
(Liability)	$ (4,641)	$ (9,675)
Weighted- Average Pay Rate	3.22%	2.38%
Weighted- Average Receive Rate	0.16%	0.19%
Weighted- Average Remaining Term (in years)	4 years 11 months 12 days	4 years 2 months 23 days
No hedge designation | Receive fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	$ 1,377,250	$ 2,359,220
Asset
Asset	0	0
(Liability)
(Liability)	$ 0	$ 0
Weighted- Average Pay Rate	0.13%	0.16%
Weighted- Average Receive Rate	0.43%	0.87%
Weighted- Average Remaining Term (in years)	11 months 19 days	1 year 25 days
No hedge designation | Receive fixed callable
Notional Disclosures [Abstract]
Notional Amount		$ 200,000
Asset
Asset		1
(Liability)
(Liability)		$ (12)
Weighted- Average Pay Rate		0.13%
Weighted- Average Receive Rate		0.15%
Weighted- Average Remaining Term (in years)		8 months 19 days
No hedge designation | Basis swaps
Notional Disclosures [Abstract]
Notional Amount	$ 1,608,911	$ 3,628,911
Asset
Asset	489	1,617
(Liability)
(Liability)	$ (280)	$ (43)
Weighted- Average Pay Rate	0.17%	0.18%
Weighted- Average Receive Rate	0.20%	0.23%
Weighted- Average Remaining Term (in years)	3 years 3 months 21 days	2 years 10 days
No hedge designation | Treasury futures
Notional Disclosures [Abstract]
Notional Amount	$ 67,600	$ 30,500
Asset
Asset	73	0
(Liability)
(Liability)	$ 0	$ (82)
Weighted- Average Forward Price (in dollars per share)	$ 130.58	$ 137.81