CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allocated share-based compensation expense	$ 131,770	$ 34,986	$ 32,957
Amortization of acquisition intangible assets	4,270	4,461	8,772
Cost of revenue
Allocated share-based compensation expense	8,931	2,503	4,114
Amortization of acquisition intangible assets	1,952	2,040	4,505
Research and development
Allocated share-based compensation expense	48,739	9,918	5,756
Sales and marketing
Allocated share-based compensation expense	19,046	8,069	8,712
Amortization of acquisition intangible assets	2,318	2,421	4,267
General and administrative
Allocated share-based compensation expense	55,054	14,496	12,301
Restructuring
Allocated share-based compensation expense	$ 0	$ 0	$ 2,074