Business Combinations - Brainjocks (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 23, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill		$ 427,928	$ 335,564	$ 327,992
Adjustment to fair value of contingent consideration for purchase of business		9,519	$ 301	$ 1,816
Brainjocks
Business Acquisition [Line Items]
Business Acquisition, Date of Acquisition Agreement	Mar. 23, 2020
Total purchase price	$ 21,200
Cash paid for acquisition	15,800
Common stock issued	2,400
Net working capital settlement	700
Initial fair value estimate of additional earnings-based contingent consideration	2,300
Acquisition maximum payout	4,800
Transaction costs	1,100
Acquired tangible assets	7,000
Identified intangible assets	8,400
Liabilities assumed	(4,900)
Goodwill	10,700
Tax deductible amount of Goodwill	$ 8,700
Current contingent consideration liability		3,600
Adjustment to fair value of contingent consideration for purchase of business		$ 1,300