Revenue - Allowance for Credit Losses (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained Earnings					$ (798,573)		$ (558,269)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest					(1,489,374)		(1,126,250)	$ (1,007,939)	$ (796,368)
Accounts Receivable, Allowances		$ 7,881	$ 6,037	$ 6,037	5,372		7,881	6,037
Allowance for Credit Losses [Roll Forward]
Beginning Balance(1)		7,881	6,037
Bad Debt Expense		6,878	10,451	3,365
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)		(10,697)	(8,607)
Ending Balance		5,372	7,881	$ 6,037
Retained Earnings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest					$ (798,573)		(558,269)	$ (364,882)	$ (79,461)
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	[1]					$ 1,310
Accounts Receivable, Allowances		9,191	9,191				$ 9,191
Allowance for Credit Losses [Roll Forward]
Beginning Balance(1)		$ 9,191
Ending Balance			$ 9,191
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Retained Earnings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	[1]					$ 1,310

[1] (2) The cumulative adjustment relates to the adoption of ASU No. 2016-13, "Measurement of Credit Losses on Financial Instruments" ("ASU 2016-13") on January 1, 2020, for which the Company recorded an adjustment to Retained Earnings to reflect the increase in the Company's Allowance for Doubtful Accounts as a result of the use of the current expected credit loss model. See Notes 2 and 3 for further information.