Revenue Recognition - Receivables and Deferred Revenue (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($)
Contract Balances [Roll Forward]
Accounts receivable, opening balance	$ 80,423
Accounts receivable, ending balance	89,807
Contract acquisition costs noncurrent, opening balance	41,021
Contract acquisition costs noncurrent, increase (decrease), net	2,441
Contract acquisition costs noncurrent, ending balance	43,462
Deferred revenue (current), opening balance	88,848
Deferred revenue (current), increase (decrease), net	18,823
Deferred revenue (current), ending balance	107,671
Deferred revenue (long-term), opening balance	409
Deferred revenue (long-term), increase (decrease), net	80
Deferred revenue (long-term), ending balance	489
Billed receivable
Contract Balances [Roll Forward]
Accounts receivable, opening balance	61,801
Accounts receivable, increase (decrease), net	(2,936)
Accounts receivable, ending balance	58,865
Unbilled receivable
Contract Balances [Roll Forward]
Accounts receivable, opening balance	18,622
Accounts receivable, increase (decrease), net	12,320
Accounts receivable, ending balance	$ 30,942