Basis of Presentation (Details) Accumulated Other Comprehensive Income (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax
Net unrealized appreciation on available-for-sale investments	$ 5,207	$ 4,455
Foreign currency translation	(6,233)	(6,469)
Accumulated other comprehensive loss	(1,026)	(2,014)
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax
Deferred tax liability on other comprehensive income	2,921	2,400
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax
Deferred income tax asset on other comprehensive loss	$ 3,135	$ 3,300