Stockholders' Equity AOCI Reclassifications (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net realized capital gains on sales of investments	$ 3,106	$ 11,062	$ 3,760
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	(4,869)	(573)	(822)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	(4,773)	1,008	(5,101)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	1,578	(2,791)	2,778	[1]
reclassifications out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net realized capital gains on sales of investments	(1,799)	(2,829)	(3,760)
Change in offsets to unrealized on investments	665	(231)	186
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	(2,451)	(146)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax	1	12	(11)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	2,425	(4,306)	(4,263)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax	(7,341)	1,550	(7,848)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	2,568	(542)	2,747
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	4,773	(1,008)	(5,101)
reclassifications out of accumulated other comprehensive income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net realized capital gains on sales of investments	(1,799)	(2,829)	(3,760)
Change in offsets to unrealized on investments	845	(224)	186
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax	0	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	0	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	2,644	2,605	(3,574)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	925	912	1,251
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	(1,719)	(1,693)	(2,323)
reclassifications out of accumulated other comprehensive income [Member] | Accumulated Other-than-Temporary Impairment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net realized capital gains on sales of investments	0	0	0
Change in offsets to unrealized on investments	(180)	(7)	0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	(2,451)	(146)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax	0	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	0	0	0
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI for Write-down of Securities, before Tax	(2,271)	(139)	0
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI for Write-down of Securities, Tax	795	49	0
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI for Write-down of Securities, Net of Tax	1,476	90	0
reclassifications out of accumulated other comprehensive income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net realized capital gains on sales of investments	0	0	0
Change in offsets to unrealized on investments	0	0	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax	1	12	(11)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	2,425	(4,306)	(4,263)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	2,426	(4,294)	(4,274)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	848	(1,503)	1,496
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	$ (1,578)	$ 2,791	$ (2,778)

[1] Other comprehensive income (loss) is recorded net of deferred income taxes and other adjustments for assumed changes in deferred acquisition costs, value of insurance in force acquired, unearned revenue reserve and policyholder liabilities.