Investment Securities, Gross Unrealized Losses for Held-to-Maturity Securities (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value		$ 473,179	$ 629,096
12 months or more, fair value		234,460	0
Fair value		707,639	629,096
Less than 12 months, unrealized losses		36,178	11,993
12 months or more, unrealized losses		29,332	0
Unrealized losses		65,510	11,993
Municipal Securities [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value		1,034
12 months or more, fair value		0
Fair value		1,034
Less than 12 months, unrealized losses		65
12 months or more, unrealized losses		0
Unrealized losses		65
Mortgage-backed Securities [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	[1]	398,924	570,119
12 months or more, fair value	[1]	234,460	0
Fair value	[1]	633,384	570,119
Less than 12 months, unrealized losses	[1]	31,318	11,764
12 months or more, unrealized losses	[1]	29,332	0
Unrealized losses	[1]	60,650	11,764
Collateralized Mortgage Obligations [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	[1]	73,221	58,977
12 months or more, fair value	[1]	0	0
Fair value	[1]	73,221	58,977
Less than 12 months, unrealized losses	[1]	4,795	229
12 months or more, unrealized losses	[1]	0	0
Unrealized losses	[1]	$ 4,795	$ 229

[1] All mortgage-backed securities and collateralized mortgage obligations were issued by an agency or government sponsored entity of the U.S. Government.