Condensed Consolidated Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 35,049	$ 35,967	$ 63,814	$ 58,738
Foreign currency translation adjustment, net of tax (benefit) of $498 and $699 for the three and six months of 2014, respectively, and ($264) and ($978) for the three and six months of 2013, respectively	1,334	(363)	2,171	(2,116)
Unrealized gain (loss) on available-for-sale investments, net of tax (benefit) of $1,665 and $135 for the three and six months of 2014, respectively, and $1,287 and $2,915 for the three and six months of 2013, respectively	2,885	2,180	245	5,001
Other Comprehensive Income (Loss), Net of Tax	4,219	1,817	2,416	2,885
Comprehensive Income	39,268	37,872	66,230	61,869
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	39,268	37,784	66,230	61,623
Net Income (Loss) Attributable to Noncontrolling Interest	0	(73)	0	(224)
Foreign currency translation adjustment attributable to noncontrolling Interest, net of tax (benefit) of $0 for the three and six months of 2014 and ($11) and ($17) for the three and six months of 2013, respectively	$ 0	$ (15)	$ 0	$ (22)