Revenue Recognition - Contract Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Capitalized Contract Cost [Line Items]
Contract cost amortization	$ 5,723	$ 2,703	$ 0
Capitalized contract cost, amortization period	5 years
Bonuses and Commissions
Capitalized Contract Cost [Line Items]
Contract cost assets	$ 4,700	1,500
Contract cost amortization	1,000	300
Contract Fulfillment Costs
Capitalized Contract Cost [Line Items]
Contract cost assets	31,800	17,600
Contract cost amortization	$ 4,700	$ 2,400