Investment Securities - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Total temporarily impaired securities, Duration Unrealized Loss Position, Less Than Twelve Months, Fair Value	$ 879,769	$ 726,921
Total temporarily impaired securities, Duration of Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Loss	(94,539)	(12,916)
Total temporarily impaired securities, Duration of Unrealized Loss Position, Twelve Months or Longer, Fair Value	177,573	51,446
Total temporarily impaired securities, Duration of Unrealized Loss Position, Twelve Months or Longer, Gross Unrealized Loss	(38,975)	(2,043)
Total temporarily impaired securities, Duration of Unrealized Loss Position, Fair Value	1,057,342	778,367
Total temporarily impaired securities, Duration of Unrealized Loss Position, Unrealized Loss	(133,514)	(14,959)
Obligations of U.S. government corporations and agencies [Member]
Available-for-sale securities, Duration of Unrealized Loss Position, Less than 12 Month, Fair Value	145,333	73,810
Available-for-sale Securities, Duration of Unrealized Loss Position, Less than 12 Month, Gross Unrealized Loss	(18,573)	(918)
Available-for-sale securities, Duration of Unrealized Loss Position, 12 Month or Longer, Fair Value	7,689
Available-for-sale Securities, Duration of Unrealized Loss Position, 12 Month or Longer, Gross Unrealized Loss	(2,559)
Available-for-sale securities, Total, Fair Value	153,022	73,810
Available-for-sale securities, Total, Unrealized Loss	(21,132)	(918)
Mortgage-Backed Securities [Member]
Available-for-sale securities, Duration of Unrealized Loss Position, Less than 12 Month, Fair Value	125,194	167,379
Available-for-sale Securities, Duration of Unrealized Loss Position, Less than 12 Month, Gross Unrealized Loss	(15,695)	(2,048)
Available-for-sale securities, Duration of Unrealized Loss Position, 12 Month or Longer, Fair Value	56,238	13,689
Available-for-sale Securities, Duration of Unrealized Loss Position, 12 Month or Longer, Gross Unrealized Loss	(8,450)	(333)
Available-for-sale securities, Total, Fair Value	181,432	181,068
Available-for-sale securities, Total, Unrealized Loss	(24,145)	(2,381)
Collateralized mortgage obligations [Member]
Available-for-sale securities, Duration of Unrealized Loss Position, Less than 12 Month, Fair Value	245,728	222,134
Available-for-sale Securities, Duration of Unrealized Loss Position, Less than 12 Month, Gross Unrealized Loss	(28,311)	(4,736)
Available-for-sale securities, Duration of Unrealized Loss Position, 12 Month or Longer, Fair Value	36,260
Available-for-sale Securities, Duration of Unrealized Loss Position, 12 Month or Longer, Gross Unrealized Loss	(5,551)
Available-for-sale securities, Total, Fair Value	281,988	222,134
Available-for-sale securities, Total, Unrealized Loss	(33,862)	(4,736)
Corporate bonds [Member]
Available-for-sale securities, Duration of Unrealized Loss Position, Less than 12 Month, Fair Value	65,177	24,173
Available-for-sale Securities, Duration of Unrealized Loss Position, Less than 12 Month, Gross Unrealized Loss	(3,346)	(270)
Available-for-sale securities, Duration of Unrealized Loss Position, 12 Month or Longer, Fair Value	1,213	504
Available-for-sale Securities, Duration of Unrealized Loss Position, 12 Month or Longer, Gross Unrealized Loss	(46)	(5)
Available-for-sale securities, Total, Fair Value	66,390	24,677
Available-for-sale securities, Total, Unrealized Loss	(3,392)	(275)
Obligations of state and political subdivisions [Member]
Available-for-sale securities, Duration of Unrealized Loss Position, Less than 12 Month, Fair Value	137,603	99,199
Available-for-sale Securities, Duration of Unrealized Loss Position, Less than 12 Month, Gross Unrealized Loss	(21,179)	(3,355)
Available-for-sale securities, Duration of Unrealized Loss Position, 12 Month or Longer, Fair Value	69,408	34,548
Available-for-sale Securities, Duration of Unrealized Loss Position, 12 Month or Longer, Gross Unrealized Loss	(22,147)	(1,675)
Available-for-sale securities, Total, Fair Value	207,011	133,747
Available-for-sale securities, Total, Unrealized Loss	(43,326)	(5,030)
Asset-backed securities [Member]
Available-for-sale securities, Duration of Unrealized Loss Position, Less than 12 Month, Fair Value	160,734	140,226
Available-for-sale Securities, Duration of Unrealized Loss Position, Less than 12 Month, Gross Unrealized Loss	(7,435)	(1,589)
Available-for-sale securities, Duration of Unrealized Loss Position, 12 Month or Longer, Fair Value	6,765	2,705
Available-for-sale Securities, Duration of Unrealized Loss Position, 12 Month or Longer, Gross Unrealized Loss	(222)	(30)
Available-for-sale securities, Total, Fair Value	167,499	142,931
Available-for-sale securities, Total, Unrealized Loss	$ (7,657)	$ (1,619)