Other Receivables and Current Assets, Other Accrued Expenses and Liabilities, and Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Other Receivables and Current Assets, Other Accrued Expenses and Liabilities, and Other Long-Term Liabilities [Abstract]
Receivables related to unrecognized revenue	$ 112,187	$ 177,679
Income taxes receivable, including overpayments and refunds	47,859	26,672
Prepaid expenses and other current assets	45,992	45,268
Total other receivables and current assets	206,038	249,619
Accrued vacation	34,478	24,336
Consumption, VAT and sales tax liabilities	18,377	36,398
Accrued expenses and other current liabilities	89,415	82,213
Total other accrued expenses and liabilities	142,270	142,947
Uncertain tax positions	67,341	64,375
Other long-term liabilities	28,742	32,051
Total other long-term liabilities	$ 96,083	$ 96,426