Fair Value of Financial Instruments - Rollforward of Balance Sheet Amounts Within Level 3 Valuation Hierarchy (Details) - Recurring - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Other Liabilities
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period	$ 0	$ 0
Total realized gains included in income	0	0
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at March 31	0	0
Purchases	0	0
Issuances	0	0
Settlements	0	0
Transfers out of Level 3	0	0
Fair value, end of period	0	0
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at March 31	0	0
Other assets
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period	26,422	28,874
Total realized gains included in income	448	512
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at March 31	0	0
Purchases	1,670	870
Issuances	0	0
Settlements	(433)	(468)
Transfers out of Level 3	0	0
Fair value, end of period	28,107	29,788
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at March 31	448	512
Available-for-sale Securities
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period	14,595	17,029
Total realized gains included in income	30	31
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at March 31	(496)	(666)
Purchases	0	0
Issuances	0	0
Settlements	(399)	(1,168)
Transfers out of Level 3	0	0
Fair value, end of period	13,730	15,226
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at March 31	$ 30	$ 31

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 the income statement for 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 gain (loss) recognized in other comprehensive income (loss) for 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 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.

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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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- Definition

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

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

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