Commitments and Contingencies (Details) - USD ($) $ in Thousands		6 Months Ended
	Feb. 28, 2020	Jun. 30, 2020	Dec. 31, 2019
Commitments and Contingencies
Shares issuable (in shares)		2,895,638
Publons
Commitments and Contingencies
Additional payments to acquire business		$ 9,500
Total purchase price		0
TrademarkVision
Commitments and Contingencies
Total purchase price		8,000
Contingent stock liability		0	$ 8,000
Decision Resources Group
Commitments and Contingencies
Additional payments to acquire business	$ 58,897	64,660
Total purchase price	$ 964,997
Contingent stock liability		$ 5,763
Shares issuable (in shares)		2,895,638
Accrued expenses and other current liabilities | Publons
Commitments and Contingencies
Contingent stock liability		$ 3,610	$ 3,100