Debt Securities Held to Maturity Continuous Unrealized Loss Position on Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, Fair Value	$ 10,029	$ 11,265
Less than 12 months, Gross unrealized (losses)	(208)	(69)
12 months or longer, Fair value	210,894	221,443
12 months or longer, Gross unrealized (losses)	(3,457)	(7,306)
Total, Fair value	220,923	232,708
Total, Gross unrealized (losses)	(3,665)	(7,375)
U.S. government and agency obligations
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, Fair Value	0	0
Less than 12 months, Gross unrealized (losses)	0	0
12 months or longer, Fair value	8,353	8,197
12 months or longer, Gross unrealized (losses)	(52)	(208)
Total, Fair value	8,353	8,197
Total, Gross unrealized (losses)	(52)	(208)
Mortgage-backed securities and collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, Fair Value	10,029	11,265
Less than 12 months, Gross unrealized (losses)	(208)	(69)
12 months or longer, Fair value	202,541	213,246
12 months or longer, Gross unrealized (losses)	(3,405)	(7,098)
Total, Fair value	212,570	224,511
Total, Gross unrealized (losses)	$ (3,613)	$ (7,167)

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-SubTopic 10
-Section 50
-Paragraph 6
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-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for less than 12 months.

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