Securities - AFS in an Unrealized Loss Position (Details) $ in Thousands	Jun. 30, 2022 USD ($) item	Dec. 31, 2021 USD ($) item
Number of Securities
Unrealized loss for less than twelve months | item	281	147
Unrealized loss for twelve months or longer | item	29	42
Total | item	310	189
Fair Value
Unrealized loss for less than twelve months	$ 1,298,247	$ 1,262,834
Unrealized loss for twelve months or longer	143,956	311,828
Total	1,442,203	1,574,662
Unrealized Loss
Unrealized loss for less than twelve months	85,352	20,376
Unrealized loss for twelve months or longer	21,126	11,261
Total	$ 106,478	$ 31,637
US Treasury Securities
Number of Securities
Unrealized loss for less than twelve months | item	3	2
Total | item	3	2
Fair Value
Unrealized loss for less than twelve months	$ 24,337	$ 14,862
Total	24,337	14,862
Unrealized Loss
Unrealized loss for less than twelve months	600	75
Total	$ 600	$ 75
Bonds
Number of Securities
Unrealized loss for less than twelve months | item	1	2
Unrealized loss for twelve months or longer | item	2	1
Total | item	3	3
Fair Value
Unrealized loss for less than twelve months	$ 4,831	$ 9,904
Unrealized loss for twelve months or longer	10,841	6,184
Total	15,672	16,088
Unrealized Loss
Unrealized loss for less than twelve months	168	94
Unrealized loss for twelve months or longer	275	59
Total	$ 443	$ 153
Residential Mortgage Backed Securities
Number of Securities
Unrealized loss for less than twelve months | item	108	52
Unrealized loss for twelve months or longer | item	8	17
Total | item	116	69
Fair Value
Unrealized loss for less than twelve months	$ 388,795	$ 548,392
Unrealized loss for twelve months or longer	58,313	104,378
Total	447,108	652,770
Unrealized Loss
Unrealized loss for less than twelve months	25,793	6,915
Unrealized loss for twelve months or longer	7,149	2,702
Total	$ 32,942	$ 9,617
Commercial Mortgage Backed Securities
Number of Securities
Unrealized loss for less than twelve months | item	10	5
Unrealized loss for twelve months or longer | item	5	14
Total | item	15	19
Fair Value
Unrealized loss for less than twelve months	$ 109,985	$ 65,636
Unrealized loss for twelve months or longer	49,979	138,619
Total	159,964	204,255
Unrealized Loss
Unrealized loss for less than twelve months	13,622	1,776
Unrealized loss for twelve months or longer	9,996	7,352
Total	$ 23,618	$ 9,128
Collateralized Mortgage Obligations
Number of Securities
Unrealized loss for less than twelve months | item	117	72
Unrealized loss for twelve months or longer | item	8	10
Total | item	125	82
Fair Value
Unrealized loss for less than twelve months	$ 748,245	$ 618,464
Unrealized loss for twelve months or longer	22,853	62,647
Total	771,098	681,111
Unrealized Loss
Unrealized loss for less than twelve months	42,634	11,316
Unrealized loss for twelve months or longer	2,950	1,148
Total	$ 45,584	$ 12,464
US States and Political Subdivisions Debt Securities
Number of Securities
Unrealized loss for less than twelve months | item	42	14
Unrealized loss for twelve months or longer | item	6
Total | item	48	14
Fair Value
Unrealized loss for less than twelve months	$ 22,054	$ 5,576
Unrealized loss for twelve months or longer	1,970
Total	24,024	5,576
Unrealized Loss
Unrealized loss for less than twelve months	2,535	200
Unrealized loss for twelve months or longer	756
Total	$ 3,291	$ 200