Shareholders' Equity - Equity Components (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 2,713,097	$ 1,877,339
Effect of adoption of new accounting standards			$ (298)
Issuance of ordinary shares in conjunction with employee equity incentive and purchase plans	10,588	5,676
Employee withholding taxes related to share-based awards	(14,594)	(14,431)
Share-based compensation	24,276	25,297
Shares repurchased	(34,546)	(13,896)
Other comprehensive income	42,057	17,490
Net income	45,991	86,511
Ending balance	$ 2,786,571	$ 1,983,986