Securities - Available for Sale Securities With Gross Unrealized Losses and Their Fair Value (Details) $ in Thousands	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Held-to-maturity securities have been in a continuous unrealized loss position, number of positions	1
Held-to-maturity securities have been in a continuous unrealized loss position, fair value	$ 20,464
Held-to-maturity securities have been in a continuous unrealized loss position, unrealized loss	162
Held-to-maturity securities have been in a continuous unrealized loss position, less than 12 months, fair value	20,464
Held-to-maturity securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	162
Held-to-maturity securities have been in a continuous unrealized loss position, 12 months or more, fair value	0
Held-to-maturity securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 0
Securities have been in a continuous unrealized loss position, number of positions	32	62
Securities have been in a continuous unrealized loss position, fair value	$ 267,658	$ 441,043
Securities have been in a continuous unrealized loss position, unrealized losses	15,400	10,101
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	66,378	146,957
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	974	1,363
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	201,280	294,086
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 14,426	$ 8,738
US States and Political Subdivisions Debt Securities [Member]
Held-to-maturity securities have been in a continuous unrealized loss position, number of positions	1
Held-to-maturity securities have been in a continuous unrealized loss position, fair value	$ 20,464
Held-to-maturity securities have been in a continuous unrealized loss position, unrealized loss	162
Held-to-maturity securities have been in a continuous unrealized loss position, less than 12 months, fair value	20,464
Held-to-maturity securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	162
Held-to-maturity securities have been in a continuous unrealized loss position, 12 months or more, fair value	0
Held-to-maturity securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 0
Other Debt Obligations [Member]
Held-to-maturity securities have been in a continuous unrealized loss position, number of positions	1
Held-to-maturity securities have been in a continuous unrealized loss position, fair value	$ 20,464
Held-to-maturity securities have been in a continuous unrealized loss position, unrealized loss	162
Held-to-maturity securities have been in a continuous unrealized loss position, less than 12 months, fair value	20,464
Held-to-maturity securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	162
Held-to-maturity securities have been in a continuous unrealized loss position, 12 months or more, fair value	0
Held-to-maturity securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 0
Securities have been in a continuous unrealized loss position, number of positions	27	29
Securities have been in a continuous unrealized loss position, fair value	$ 205,155	$ 222,187
Securities have been in a continuous unrealized loss position, unrealized losses	15,217	8,162
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	12,602	25,451
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	819	108
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	192,553	196,736
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 14,398	$ 8,054
FNMA [Member]
Securities have been in a continuous unrealized loss position, number of positions	2	8
Securities have been in a continuous unrealized loss position, fair value	$ 40,161	$ 67,618
Securities have been in a continuous unrealized loss position, unrealized losses	147	426
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	31,434	19,073
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	119	138
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	8,727	48,545
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 28	$ 288
Collateralized Mortgage Backed Securities [Member]
Securities have been in a continuous unrealized loss position, number of positions	5	33
Securities have been in a continuous unrealized loss position, fair value	$ 62,503	$ 218,856
Securities have been in a continuous unrealized loss position, unrealized losses	183	1,939
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	53,776	121,506
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	155	1,255
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	8,727	97,350
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 28	$ 684
Corporate Debt Securities [Member]
Securities have been in a continuous unrealized loss position, number of positions	14	16
Securities have been in a continuous unrealized loss position, fair value	$ 110,535	$ 123,050
Securities have been in a continuous unrealized loss position, unrealized losses	9,465	6,950
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	0	0
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	0	0
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	110,535	123,050
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 9,465	$ 6,950
Collateralized Loan Obligations [Member]
Securities have been in a continuous unrealized loss position, number of positions	13	13
Securities have been in a continuous unrealized loss position, fair value	$ 94,620	$ 99,137
Securities have been in a continuous unrealized loss position, unrealized losses	5,752	1,212
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	12,602	25,451
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	819	108
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	82,018	73,686
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 4,933	$ 1,104
REMIC and CMO [Member]
Securities have been in a continuous unrealized loss position, number of positions	2	23
Securities have been in a continuous unrealized loss position, fair value	$ 7,818	$ 120,989
Securities have been in a continuous unrealized loss position, unrealized losses	24	1,440
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	7,818	102,384
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	24	1,117
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	0	18,605
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 0	$ 323
FHLMC [Member]
Securities have been in a continuous unrealized loss position, number of positions	1	1
Securities have been in a continuous unrealized loss position, fair value	$ 14,524	$ 30,200
Securities have been in a continuous unrealized loss position, unrealized losses	12	73
Securities have been in a continuous unrealized loss position, less than 12 months, fair value	14,524	0
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses	12	0
Securities have been in a continuous unrealized loss position, 12 months or more, fair value	0	30,200
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses	$ 0	$ 73
GNMA [Member]
Securities have been in a continuous unrealized loss position, number of positions		1
Securities have been in a continuous unrealized loss position, fair value		$ 49
Securities have been in a continuous unrealized loss position, unrealized losses		0
Securities have been in a continuous unrealized loss position, less than 12 months, fair value		49
Securities have been in a continuous unrealized loss position, less than 12 months, unrealized losses		0
Securities have been in a continuous unrealized loss position, 12 months or more, fair value		0
Securities have been in a continuous unrealized loss position, 12 months or more, unrealized losses		$ 0