Investment Securities - Schedule of Amortized Cost and Fair Value of Debt Securities, Aggregated By Earlier of Guaranteed Call Date or Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Within One Year, Amortized Cost	$ 12,004
Available for sale securities, Within One Year, Fair Value	11,924
Available for sale securities, After One, But Within Five Years, Amortized Cost	47,074
Available for sale securities, After One, But Within Five Years, Fair Value	46,548
Available for sale securities, After Five, But Within Ten Years, Amortized Cost	32,365
Available for sale securities, After Five, But Within Ten Years, Fair Value	31,712
Available for sale securities, After Ten Years, Amortized Cost	55,934
Available for sale securities, After Ten Years, Fair Value	54,578
Available for sale securities, Total, Amortized Cost	147,377
Available for sale securities, Total, Fair Value	144,762
Held to maturity securities, Within One Year, Amortized Cost	3,484
Held to maturity securities, Within One Year, Fair Value	3,497
Held to maturity securities, After One, But Within Five Years, Amortized Cost	48,047
Held to maturity securities, After One, But Within Five Years, Fair Value	48,163
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	96,556
Held to maturity securities, After Five, But Within Ten Years, Fair Value	98,130
Held to maturity securities, After Ten Years, Amortized Cost	150,743
Held to maturity securities, After Ten Years, Fair Value	150,817
Held to maturity securities, Amortized Cost	298,830	$ 282,869
Held to maturity securities, Fair Value	300,607	281,310
Available for sale securities and Held to maturity securities, Within One Year, Amortized Cost	15,488
Available for sale securities and Held to maturity securities, Within One Year, Fair Value	15,421
Available for sale securities and Held to maturity securities, After One, But Within Five Years, Amortized Cost	95,121
Available for sale securities and Held to maturity securities, After One, But Within Five Years, Fair Value	94,711
Available for sale securities and Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	128,921
Available for sale securities and Held to maturity securities, After Five, But Within Ten Years, Fair Value	129,842
Available for sale securities and Held to maturity securities, After Ten Years, Amortized Cost	206,677
Available for sale securities and Held to maturity securities, After Ten Years, Fair Value	205,395
Available for sale securities and Held to maturity securities, Total, Amortized Cost	446,207
Available for sale securities and Held to maturity securities, Total, Fair Value	445,369
U.S. GSE Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Within One Year, Amortized Cost	10,000
Available for sale securities, Within One Year, Fair Value	9,926
Available for sale securities, After One, But Within Five Years, Amortized Cost	45,000
Available for sale securities, After One, But Within Five Years, Fair Value	44,502
Available for sale securities, Total, Amortized Cost	55,000
Available for sale securities, Total, Fair Value	54,428
Held to maturity securities, After One, But Within Five Years, Amortized Cost	27,571
Held to maturity securities, After One, But Within Five Years, Fair Value	27,441
Held to maturity securities, Amortized Cost	27,571
Held to maturity securities, Fair Value	27,441
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, After One, But Within Five Years, Amortized Cost	68
Available for sale securities, After One, But Within Five Years, Fair Value	69
Available for sale securities, After Five, But Within Ten Years, Amortized Cost	32,365
Available for sale securities, After Five, But Within Ten Years, Fair Value	31,712
Available for sale securities, After Ten Years, Amortized Cost	55,934
Available for sale securities, After Ten Years, Fair Value	54,578
Available for sale securities, Total, Amortized Cost	88,367
Available for sale securities, Total, Fair Value	86,359
Held to maturity securities, Within One Year, Amortized Cost	24
Held to maturity securities, Within One Year, Fair Value	24
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	53,879
Held to maturity securities, After Five, But Within Ten Years, Fair Value	53,855
Held to maturity securities, After Ten Years, Amortized Cost	137,776
Held to maturity securities, After Ten Years, Fair Value	137,569
Held to maturity securities, Amortized Cost	191,679
Held to maturity securities, Fair Value	191,448
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Within One Year, Amortized Cost	2,004
Available for sale securities, Within One Year, Fair Value	1,998
Available for sale securities, After One, But Within Five Years, Amortized Cost	2,006
Available for sale securities, After One, But Within Five Years, Fair Value	1,977
Available for sale securities, Total, Amortized Cost	4,010
Available for sale securities, Total, Fair Value	3,975
Held to maturity securities, After One, But Within Five Years, Amortized Cost	6,974
Held to maturity securities, After One, But Within Five Years, Fair Value	6,986
Held to maturity securities, Amortized Cost	6,974
Held to maturity securities, Fair Value	6,986
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Within One Year, Amortized Cost	3,460
Held to maturity securities, Within One Year, Fair Value	3,473
Held to maturity securities, After One, But Within Five Years, Amortized Cost	13,502
Held to maturity securities, After One, But Within Five Years, Fair Value	13,736
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	42,677
Held to maturity securities, After Five, But Within Ten Years, Fair Value	44,275
Held to maturity securities, After Ten Years, Amortized Cost	12,967
Held to maturity securities, After Ten Years, Fair Value	13,248
Held to maturity securities, Amortized Cost	72,606	75,208
Held to maturity securities, Fair Value	$ 74,732	$ 76,150

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