Securities - Amortized Cost and Fair Value of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Securities held-to-maturity, amortized cost	$ 58,739	$ 58,888
Securities held-to-maturity, fair value	63,529	62,112
Securities held-to-maturity, gross Unrecognized gains	4,790	3,224
Securities held-to-maturity, allowance for credit losses	(907)
Securities available for sale, amortized cost, total other securities	646,112	778,294
Securities available for sale, fair value	647,974	772,500
Securities available for sale, gross unrealized gains	9,628	4,307
Securities available for sale, gross unrealized losses	7,766	10,101
Other Securities [Member]
Securities available for sale, amortized cost, total other securities	1,295	1,332
Securities available for sale, fair value	1,295	1,332
Securities available for sale, gross unrealized gains	0	0
Securities available for sale, gross unrealized losses	0	0
US Government Agencies Debt Securities [Member]
Securities available for sale, amortized cost, total other securities	6,452
Securities available for sale, fair value	6,453
Securities available for sale, gross unrealized gains	2
Securities available for sale, gross unrealized losses	1
Corporate Debt Securities [Member]
Securities available for sale, amortized cost, total other securities	130,000	130,000
Securities available for sale, fair value	123,865	123,050
Securities available for sale, gross unrealized gains	131	0
Securities available for sale, gross unrealized losses	6,266	6,950
US States and Political Subdivisions Debt Securities [Member]
Securities held-to-maturity, amortized cost		50,954
Securites held-to-maturity, amortized cost	50,825
Securities held-to-maturity, fair value	54,538	53,998
Securities held-to-maturity, gross Unrecognized gains	3,713	3,044
Securities held-to-maturity, allowance for credit losses	(907)
Securities available for sale, amortized cost, total other securities		12,797
Securities available for sale, fair value		12,916
Securities available for sale, gross unrealized gains		119
Securities available for sale, gross unrealized losses		0
Mutual Fund Debt Securities [Member]
Securities available for sale, amortized cost, total other securities	12,703	12,216
Securities available for sale, fair value	12,703	12,216
Securities available for sale, gross unrealized gains	0	0
Securities available for sale, gross unrealized losses	0	0
Collateralized Debt Obligations [Member]
Securities available for sale, amortized cost, total other securities	100,561	100,349
Securities available for sale, fair value	99,198	99,137
Securities available for sale, gross unrealized gains	0	0
Securities available for sale, gross unrealized losses	1,363	1,212
Other Debt Obligations [Member]
Securities held-to-maturity, amortized cost	49,918	50,954
Securites held-to-maturity, amortized cost	50,825
Securities held-to-maturity, fair value	54,538	53,998
Securities held-to-maturity, gross Unrecognized gains	3,713	3,044
Securities held-to-maturity, allowance for credit losses	(907)
Securities available for sale, fair value	243,514	248,651
Collateralized Mortgage Backed Securities [Member]
Securities held-to-maturity, amortized cost	7,914	7,934
Securities held-to-maturity, fair value	8,991	8,114
Securities held-to-maturity, gross Unrecognized gains	1,077	180
Securities held-to-maturity, allowance for credit losses	0
Securities available for sale, amortized cost, total other securities	395,101	521,600
Securities available for sale, fair value	404,460	523,849
Securities available for sale, gross unrealized gains	9,495	4,188
Securities available for sale, gross unrealized losses	136	1,939
REMIC and CMO [Member]
Securities available for sale, amortized cost, total other securities	175,142	348,236
Securities available for sale, fair value	180,877	348,989
Securities available for sale, gross unrealized gains	5,735	2,193
Securities available for sale, gross unrealized losses	0	1,440
GNMA [Member]
Securities available for sale, amortized cost, total other securities	13,009	653
Securities available for sale, fair value	13,053	704
Securities available for sale, gross unrealized gains	66	51
Securities available for sale, gross unrealized losses	22	0
FNMA [Member]
Securities held-to-maturity, amortized cost	7,914	7,934
Securities held-to-maturity, fair value	8,991	8,114
Securities held-to-maturity, gross Unrecognized gains	1,077	180
Securities held-to-maturity, allowance for credit losses	0
Securities available for sale, amortized cost, total other securities	143,154	104,235
Securities available for sale, fair value	146,169	104,882
Securities available for sale, gross unrealized gains	3,046	1,073
Securities available for sale, gross unrealized losses	31	426
FHLMC [Member]
Securities available for sale, amortized cost, total other securities	63,796	68,476
Securities available for sale, fair value	64,361	69,274
Securities available for sale, gross unrealized gains	648	871
Securities available for sale, gross unrealized losses	83	73
Available for Sale Securities Excluding Mortgage Backed Securities [Member]
Securities available for sale, amortized cost, total other securities	251,011	256,694
Securities available for sale, fair value	243,514	248,651
Securities available for sale, gross unrealized gains	133	119
Securities available for sale, gross unrealized losses	$ 7,630	$ 8,162

Amount of investment in debt security measured at amortized cost, before allowance for credit losses.

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).

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