Condensed Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Operating activities    
Net loss $ (97,169) $ (93,100)
Adjustments to reconcile net loss to net cash provided by operating activities    
Depreciation and amortization expense 23,837 16,001
Stock-based compensation expense 101,309 90,571
Deferred income taxes 465 239
Changes in operating assets and liabilities    
Accounts receivable, net 72,493 (2,176)
Prepaid expenses, deposits and other assets 19,519 (419)
Income taxes receivable (97) 72
Deferred revenue 30,072 31,654
Accounts payable and accrued liabilities (16,421) 18,086
Income taxes payable 523 105
Net cash provided by operating activities 134,531 61,033 [1]
Investing activities    
Purchases of property and equipment (33,860) (23,452)
Business combination 0 (16,399)
Net cash used in investing activities (33,860) (39,851)
Financing activities    
Proceeds from issuance of common stock 21,646 18,040
Repurchases of common stock (40,014) 0
Net cash provided by (used in) financing activities (18,368) 18,040 [1]
Effect of exchange rate changes on cash and cash equivalents 1,884 (375)
Net increase in cash and cash equivalents 84,187 38,847
Cash and cash equivalents    
Beginning of period 908,717 795,900
End of period 992,904 834,747
Non-cash activities    
Accrued purchases of property and equipment 1,875 14,663
Asset retirement obligations recognized, net $ 0 $ 70
[1] (1) We adopted Accounting Standards Update ("ASU") 2016-09 in the first quarter of 2017. Prior to the adoption of ASU 2016-09, excess tax benefits related to stock awards were required to be presented as an inflow from financing activities and an outflow from operating activities on the statement of cash flows. Under the new standard, all tax-related cash flows resulting from share-based payments are reported as operating activities. We adopted the new requirement retrospectively, and for the six months ended June 30, 2016, this resulted in an increase to net cash provided by operating activities of $0.6 million and a corresponding decrease to net cash provided by (used in) financing activities of $0.6 million.