Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period		$ (66,698)
Other comprehensive income (loss)		74,808	$ (31,514)
Accumulated Other Comprehensive Income (Loss), End of Period		8,124
Net realized investment gains		25,457	19,044
Income before income taxes		174,676	168,717
Income before taxes		582,459	551,046
Tax effect		54,428	50,273
After-tax amounts reclassified		120,248	118,444
Unrealized investment gains, pre-tax		114,390	24,536
Unrealized investment gains, tax effect		(37,535)	(8,245)
Unrealized investment gains, after-tax amounts		76,855	16,291
Currency translation adjustment, pre-tax		(2,047)	(47,805)
Currency translation adjustment, tax effect		0	0
Change in unrealized currency translation adjustments		(2,047)	(47,805)
Other comprehensive income (loss), pre-tax		112,343	(23,269)
Other comprehensive income (loss), tax effect		(37,535)	(8,245)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period		180,695	306,199
Other comprehensive income (loss) before reclassifications		78,242	24,592
Amounts reclassified from AOCI		(1,387)	(8,301)
Other comprehensive income (loss)		76,855	16,291
Unrealized investment gain related to non-controlling interest		14	22
Accumulated Other Comprehensive Income (Loss), End of Period		257,564	322,512
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period		(247,393)	(122,649)
Other comprehensive income (loss) before reclassifications		(2,047)	(47,805)
Amounts reclassified from AOCI		0	0
Other comprehensive income (loss)		(2,047)	(47,805)
Unrealized investment gain related to non-controlling interest		0	0
Accumulated Other Comprehensive Income (Loss), End of Period		(249,440)	(170,454)
Change in unrealized currency translation adjustments		(2,047)	(47,805)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period		(66,698)	183,550
Other comprehensive income (loss) before reclassifications		76,195	(23,213)
Amounts reclassified from AOCI		(1,387)	(8,301)
Other comprehensive income (loss)		74,808	(31,514)
Unrealized investment gain related to non-controlling interest		14	22
Accumulated Other Comprehensive Income (Loss), End of Period		8,124	152,058
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net realized investment gains	[1]	(2,134)	(12,771)
Tax effect	[2]	747	4,470
After-tax amounts reclassified		(1,387)	(8,301)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes		0	0
Tax effect	[2]	0	0
After-tax amounts reclassified		0	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes		(2,134)	(12,771)
Tax effect	[2]	(747)	(4,470)
After-tax amounts reclassified		$ (1,387)	$ (8,301)

[1] Net investment (gains) losses in the consolidated statements of income.

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