Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
Other comprehensive income (before tax) [Abstract]
Change in unrealized gains and losses on investments	$ 19,721		$ 39,661
Benefit plan adjustments	(700)		(1,486)
Unrealized foreign currency translation adjustment	(3,102)		1,931
Other comprehensive income (loss)	15,919		40,106
Other comprehensive income (tax) [Abstract]
Change in unrealized gains and losses on investments	(6,876)		(13,871)
Benefit plan adjustments	245		520
Unrealized foreign currency translation adjustment	1,088		(678)
Other comprehensive income (loss)	(5,543)		(14,029)
Other comprehensive income (valuation allowance) [Abstract]
Change in unrealized gains and losses on investments	6,718		13,808
Benefit plan adjustments	(245)		(520)
Unrealized foreign currency translation adjustment	0		0
Other comprehensive income (loss)	6,473		13,288
Other comprehensive income (net of tax) [Abstract]
Change in unrealized investment gains and losses on investments	19,563		39,598
Benefit plan adjustments	(700)		(1,486)
Unrealized foreign currency translation adjustment	(2,014)		1,253
Other comprehensive income (loss)	16,849		39,365
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period, before tax	(41,613)		(77,216)
Other comprehensive income (loss) before reclassifications	27,853		38,603
Amounts reclassified from accumulated other comprehensive income (loss)	11,934		(1,503)
Net current period other comprehensive income (loss)	15,919		40,106
Balance at end of period, before tax	(25,694)		(37,110)
Tax effect	(38,798)		(41,251)		(39,728)	[1]
Total accumulated other comprehensive income (loss), net of tax	(64,492)		(78,361)		(81,341)
Tax Effect due to valuation allowance (in hundredths)	35.00%
Unrealized gains and losses on available-for-sale securities [Member]
Other comprehensive income (before tax) [Abstract]
Other comprehensive income (loss)	19,721		39,661
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period, before tax	7,148		(84,634)
Other comprehensive income (loss) before reclassifications	30,955		36,672
Amounts reclassified from accumulated other comprehensive income (loss)	11,234	[2]	(2,989)	[2]
Net current period other comprehensive income (loss)	19,721		39,661
Balance at end of period, before tax	26,869		(44,973)
Tax effect	(64,857)		(64,119)		(64,699)	[1]
Total accumulated other comprehensive income (loss), net of tax	(37,988)		(109,092)		(57,551)
Defined benefit plans [Member]
Other comprehensive income (before tax) [Abstract]
Other comprehensive income (loss)	(700)		(1,486)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period, before tax	(55,878)		(3,766)
Other comprehensive income (loss) before reclassifications	0		0
Amounts reclassified from accumulated other comprehensive income (loss)	700	[3]	1,486
Net current period other comprehensive income (loss)	(700)		(1,486)
Balance at end of period, before tax	(56,578)		(5,252)
Tax effect	26,940		26,940		26,940	[1]
Total accumulated other comprehensive income (loss), net of tax	(29,638)		21,688		(28,938)
Foreign currency translation [Member]
Other comprehensive income (before tax) [Abstract]
Other comprehensive income (loss)	(3,102)		1,931
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period, before tax	7,117		11,184
Other comprehensive income (loss) before reclassifications	(3,102)		1,931
Amounts reclassified from accumulated other comprehensive income (loss)	0		0
Net current period other comprehensive income (loss)	(3,102)		1,931
Balance at end of period, before tax	4,015		13,115
Tax effect	(881)		(4,072)		(1,969)	[1]
Total accumulated other comprehensive income (loss), net of tax	$ 3,134		$ 9,043		$ 5,148

[1] Tax effect does not approximate 35% due to amounts of tax benefits not provided in various periods due to our tax valuation allowance.

[2] During the three months ended March 31, 2015 and 2014, we realized net investment gains (losses) that at the end of the prior quarter had been classified in net unrealized gains (losses) of $11.2 million and ($3.0) million, respectively,. As a result, these amounts were reclassified to the Consolidated Statement of Operations and included in Realized investment gains (losses)

[3] During the three months ended March 31, 2015 and 2014, other comprehensive income related to benefit plans of $0.7 million and $1.5 million was reclassified to the Consolidated Statement of Operations and included in Underwriting and other expenses, net.