Fair Value of Financial Instruments - Rollforward of Balance Sheet Amounts Within Level 3 Valuation Hierarchy (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Transfers out of Level 3			$ 0
Recurring \| Other assets
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period	$ 31,522	$ 23,578	26,422	$ 28,874
Total realized gains included in income	1,264	81	2,193	2,858
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at period-end	0	0	0	0
Purchases	1,777	2,455	6,965	7,273
Issuances	0	0	0	0
Settlements	615	932	1,632	1,657
Transfers out of Level 3	0	0	0	(12,166)
Fair value, end of period	33,948	25,182	33,948	25,182
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at period-end	1,264	81	2,193	2,858
Recurring \| Available-for-sale Securities
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period	15,263	15,290	14,595	17,029
Total realized gains included in income	29	30	87	90
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at period-end	574	34	1,583	(597)
Purchases	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	(399)	(1,168)
Transfers out of Level 3	0	0	0	0
Fair value, end of period	15,866	15,354	15,866	15,354
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at period-end	$ 29	$ 30	$ 87	$ 90

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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-Section 50
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- Definition

Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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-Publisher FASB
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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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- Definition

Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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-Name Accounting Standards Codification
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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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