Condensed Consolidated Statement of Comprehensive Income - Scenario, Unspecified [Domain] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 38,916	$ 35,049	$ 60,794	$ 63,814
Foreign currency translation adjustment, net of tax expense of zero and zero for the three and six months of 2015, respectively, and $498 and $699 for the three and six months of 2014, respectively	7,112	1,334	(8,125)	2,171
Unrealized gain (loss) on available-for-sale investments, net of tax expense (benefit) of ($2,448) and ($2,616) for the three and six months of 2015, respectively, and $1,665 and $135 for the three and six months of 2014, respectively	(3,934)	2,885	(3,554)	245
Other Comprehensive Income (Loss), Net of Tax	3,178	4,219	(11,679)	2,416
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 42,094	$ 39,268	$ 49,115	$ 66,230