Investment Securities - Gross Unrealized Losses of Aggregated by Investment Category and Length of Time that Individual Securities have been in Continuous Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months	$ 46,293	$ 902
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months	(353)	(98)
Temporarily Impaired Securities, Available for sale securities, Fair Value, 12 months or longer	75,702	164,808
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, 12 months or longer	(657)	(4,147)
Temporarily Impaired Securities, Available for sale securities, Fair Value	121,995	165,710
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses	(1,010)	(4,245)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months	19,772	51,063
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months	(93)	(410)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, 12 months or longer	17,928	128,876
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, 12 months or longer	(84)	(2,580)
Temporarily Impaired Securities, Held to maturity securities, Fair Value	37,700	179,939
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses	(177)	(2,990)
Temporarily Impaired Securities, Fair Value, Less than 12 months	66,065	51,965
Temporarily Impaired Securities, Unrealized Losses, Less than 12 months	(446)	(508)
Temporarily Impaired Securities, Fair Value, 12 months or longer	93,630	293,684
Temporarily Impaired Securities, Unrealized Losses, 12 months or longer	(741)	(6,727)
Temporarily Impaired Securities, Fair Value	159,695	345,649
Temporarily Impaired Securities, Unrealized Losses	(1,187)	(7,235)
U.S. GSE Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months	12,912
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months	(88)
Temporarily Impaired Securities, Available for sale securities, Fair Value, 12 months or longer	24,936	74,039
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, 12 months or longer	(64)	(965)
Temporarily Impaired Securities, Available for sale securities, Fair Value	37,848	74,039
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses	(152)	(965)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months		4,995
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months		(5)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, 12 months or longer	5,000	27,338
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, 12 months or longer		(233)
Temporarily Impaired Securities, Held to maturity securities, Fair Value	5,000	32,333
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses		(238)
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months	33,381
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months	(265)
Temporarily Impaired Securities, Available for sale securities, Fair Value, 12 months or longer	50,766	86,815
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, 12 months or longer	(593)	(3,121)
Temporarily Impaired Securities, Available for sale securities, Fair Value	84,147	86,815
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses	(858)	(3,121)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months	14,838	30,719
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months	(27)	(216)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, 12 months or longer	12,928	93,225
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, 12 months or longer	(84)	(2,074)
Temporarily Impaired Securities, Held to maturity securities, Fair Value	27,766	123,944
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses	(111)	(2,290)
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months		902
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months		(98)
Temporarily Impaired Securities, Available for sale securities, Fair Value, 12 months or longer		3,954
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, 12 months or longer		(61)
Temporarily Impaired Securities, Available for sale securities, Fair Value		4,856
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses		(159)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months		6,865
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months		(107)
Temporarily Impaired Securities, Held to maturity securities, Fair Value		6,865
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses		(107)
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months	4,934	8,484
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months	(66)	(82)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, 12 months or longer		8,313
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, 12 months or longer		(273)
Temporarily Impaired Securities, Held to maturity securities, Fair Value	4,934	16,797
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses	$ (66)	$ (355)