Accumulated Other Comprehensive Income/ (Loss) - Changes in AOCI (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($)
Changes in accumulated other comprehensive income (loss)
Balance at December 31, 2016 (Restated)	$ 529,797
Balance at June 30, 2017	473,964
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss)
Balance at December 31, 2016 (Restated)	(42,350)
Other comprehensive income	14,808
Tax effect	(713)
Total comprehensive income	14,095
Balance at June 30, 2017	(28,255)
Foreign Currency Translation Adjustment
Changes in accumulated other comprehensive income (loss)
Balance at December 31, 2016 (Restated)	(37,311)
Other comprehensive income	12,724
Tax effect	0
Total comprehensive income	12,724
Balance at June 30, 2017	(24,587)
Net income (Loss) on Intra-Entity Foreign Currency Transactions
Changes in accumulated other comprehensive income (loss)
Balance at December 31, 2016 (Restated)	(5,017)
Other comprehensive income	2,056
Tax effect	(703)
Total comprehensive income	1,353
Balance at June 30, 2017	(3,664)
Unrealized Gains (Losses) on Available-for-Sale Securities
Changes in accumulated other comprehensive income (loss)
Balance at December 31, 2016 (Restated)	(22)
Other comprehensive income	28
Tax effect	(10)
Total comprehensive income	18
Balance at June 30, 2017	$ (4)