Consolidated Statements Of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 85,066	$ 97,147	$ 80,296
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	29,294	(7,352)	(44,569)
Unrealized gain on available-for-sale investments	0	0	611
Reclassification of cumulative translation adjustment associated with liquidated and planned sale of subsidiaries	1,702	0	0
Reclassification adjustment associated with the sale of available-for-sale investments	0	(611)	0
Pension liability adjustments, net of income tax (benefit) expense of $(26), $82, and $(45) for year ended December 31, 2017, 2016, and 2015	(232)	462	(142)
Other comprehensive income (loss)	30,764	(7,501)	(44,100)
Comprehensive income (loss)	$ 115,830	$ 89,646	$ 36,196