Contract Balances - Valuation And Qualifying Accounts Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Contract Balances
Allowance for Doubtful Accounts Receivable, Beginning Balance	$ 72,278	$ 19,280	$ 16,966
Current Period Provision for Expected Credit Losses	54,083	84,697	69,866
Write-offs Charged Against Allowance	(87,919)	(56,075)	(67,552)
Boost Acquisition	92	24,376
Allowance for Doubtful Accounts Receivable, Ending Balance	$ 38,534	$ 72,278	$ 19,280