Condensed Consolidated Statements of Comprehensive Income (Unaudited) Condensed Statements of Comprehensive Income - Parenthetical - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Income tax expense on foreign currency translation Adjustments	$ 0	$ 0	$ 0	$ 0
Income tax expense on net unrealized gain (loss) from available-for-sale investments	0	0	0	0
Income tax expense on reclassification to statements of operations of gain (loss) from available-for-sale investments	$ 0	$ 0	$ 0	$ 0