Accumulated Other Comprehensive Loss - Summary of the Tax Effects Allocated to Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Loss
Reclassification adjustment for loss (gain) included in earnings, Before-tax-amount		$ 2	$ 1,078
Reclassification of other-than-temporary impairment loss included in earnings, Before-tax-amount			63
Reclassification into retained earnings for the adoption of ASU, Before-tax-amount	[1]		932
Total before income taxes		812	1,261
Other comprehensive loss, Tax (expense) or benefit	[2]	(206)	(632)
Total other comprehensive income, net of tax		606	629
Unrealized gain on available for sale securities
Accumulated Other Comprehensive Loss
Unrealized gain (loss) on investments, Net-of-tax amount		604
Reclassification adjustment for loss (gain) included in earnings, Before-tax-amount		2	1,078
Reclassification adjustment for loss (gain) included in earnings, Tax (expense) or benefit			(273)
Reclassification adjustment for loss (gain) included in earnings, Net-of-tax amount		2	805
Reclassification of other-than-temporary impairment loss included in earnings, Before-tax-amount			63
Reclassification adjustment for other-than-temporary impairment loss included in earnings, Tax (expense) or benefit			(16)
Reclassification adjustment for other-than-temporary impairment loss included in earnings, Net-of-tax amount			47
Total before income taxes		812	1,261
Other comprehensive loss, Tax (expense) or benefit		(206)	(632)
Total other comprehensive income, net of tax		606	629
Unrealized gain on available for sale securities | ASU 2016-01
Accumulated Other Comprehensive Loss
Reclassification into retained earnings for the adoption of ASU, Before-tax-amount			932
Reclassification into retained earnings for the adoption of ASU, Tax (expense) or benefit			(236)
Reclassification into retained earnings for the adoption of ASU, Net-of-tax amount			696
Unrealized gain on available for sale securities | ASU 2018-02
Accumulated Other Comprehensive Loss
Reclassification into retained earnings for the adoption of ASU, Tax (expense) or benefit			(313)
Reclassification into retained earnings for the adoption of ASU, Net-of-tax amount			(313)
Unrestricted available-for-sale, Debt securities | Unrealized gain on available for sale securities
Accumulated Other Comprehensive Loss
Unrealized gain (loss) on investments, Before-tax amount		799	(803)
Unrealized gain (loss) on investments, Tax (expense) or benefit		(203)	204
Unrealized gain (loss) on investments, Net-of-tax amount		596	(599)
Restricted | Unrealized gain on available for sale securities
Accumulated Other Comprehensive Loss
Unrealized gain (loss) on investments, Before-tax amount		11	(9)
Unrealized gain (loss) on investments, Tax (expense) or benefit		(3)	2
Unrealized gain (loss) on investments, Net-of-tax amount		$ 8	$ (7)

[1] The reclassification into retained earnings for the three months ended March 31, 2018 relates to the adoption of Accounting Standards Update (“ASU”) 201601 Financial Instruments - Overall, as amended (“ASU 201601”). The new guidance was effective January 1, 2018, and required equity investments to be measured at fair value with changes in fair value recognized in results of operations rather than the condensed consolidated statements of comprehensive income.

[2] Income tax expense for the three months ended March 31, 2018 includes $0.3 million of income tax expense related to the adoption of ASU 201802 Income Statement - Reporting Comprehensive Income (“ASU 201802”). The new guidance was effective January 1, 2018, and allowed a reclassification from accumulated other comprehensive loss to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (the “Tax Act”).