Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income, Net of Tax, Beginning Balance	$ 118,651
Other comprehensive income	43,570	(27,171)
Accumulated Other Comprehensive Income, Net of Tax, Ending Balance	162,221
Accumulated Net Unrealized Investment Gain [Member]
Accumulated Other Comprehensive Income, Net of Tax, Beginning Balance	99,960
Other comprehensive income	42,350
Accumulated Other Comprehensive Income, Net of Tax, Ending Balance	142,310
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income, Net of Tax, Beginning Balance	18,691
Other comprehensive income	1,220
Accumulated Other Comprehensive Income, Net of Tax, Ending Balance	19,911
Accumulated other comprehensive income [Member]
Other comprehensive income	$ 43,570