Revenue Recognition - Receivables and Deferred Revenue (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Contract Balances [Roll Forward]
Accounts receivable, opening balance	$ 80,423
Accounts receivable, ending balance	83,160
Contract acquisition costs noncurrent, opening balance	41,021
Contract acquisition costs noncurrent, increase (decrease), net	2,684
Contract acquisition costs noncurrent, ending balance	43,705
Deferred revenue (current), opening balance	88,848
Deferred revenue (current), increase (decrease), net	14,057
Deferred revenue (current), ending balance	102,905
Deferred revenue (long-term), opening balance	409
Deferred revenue (long-term), increase (decrease), net	(230)
Deferred revenue (long-term), ending balance	179
Billed receivable
Contract Balances [Roll Forward]
Accounts receivable, opening balance	61,801
Accounts receivable, increase (decrease), net	(12,164)
Accounts receivable, ending balance	49,637
Unbilled receivable
Contract Balances [Roll Forward]
Accounts receivable, opening balance	18,622
Accounts receivable, increase (decrease), net	14,901
Accounts receivable, ending balance	$ 33,523