Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from AOCI, Current Period, Tax	$ 414
AOCI Tax, Attributable to Parent	(2,880)	$ 2,823
Pretax Cumulative Effect of New Accounting Principal in Period of Adoption		(12,300)
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, Tax, Portion Attributable to Parent		1,549
Tax Cumulative Effect of New Accounting Principal in Period of Adoption		2,962
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income and (Loss), Pre-Tax Amount, Beginning of period	12,044	1,464	$ 2,640
Change in net unrealized gain (loss) on investments, Pre-Tax Amount	(22,264)	10,647	(629)
Reclassification adjustment for realized gains, Pre-Tax Amount	(1,655)	(67)	(547)
Accumulated Other Comprehensive Income and (Loss), Pre-Tax Amount, End of period	(11,910)	12,044	1,464
Accumulated Other Comprehensive Income (Loss), Tax (Expense) Benefit, Beginning of period		642	1,020
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax		(3,747)	167
Reclassification adjustment for realized losses, Tax (Expense) Benefit		17	211
Accumulated Other Comprehensive Income (Loss), Tax (Expense) Benefit, End of period			642
Accumulated Other Comprehensive Income (Loss), Net-of-Tax Amount, Beginning of period	9,221	822	1,620
Change in net unrealized gain (loss) on investments, Net-of-Tax Amount		6,900	(462)
Reclassification adjustment for realized gains, Net-of-Tax Amount		(50)	(336)
OCI, before Reclassifications, Net of Tax, Attributable to Parent	(7,672)
Accumulated Other Comprehensive Income (Loss), Net-of-Tax Amount, End of period	(9,030)	9,221	$ 822
Cumulative Effect of New Accounting Principle in Period of Adoption	0	(9,338)
AOCI Before Tax Attributable to Parent after Cumulative Effect Adjustment		(256)
AOCI Tax Attributable to Parent After Cumulative Effect Adjustment		139
AOCI Net of Tax After Cumulative Effect Adjustment		(117)
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, before Tax, Portion Attributable to Parent		0
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	1,655
OCI, before Reclassifications, before Tax, Attributable to Parent	(9,999)
Other Comprehensive Income (Loss) before Reclassifications, Tax	(2,327)
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent	$ 1,241
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, Net of Tax, Portion Attributable to Parent		$ 1,549