Business and Summary of Significant Accounting Policies - Activity of Deferred Contract Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Capitalized Contract Cost [Roll Forward]
Beginning balance	$ 59,434	$ 50,176
Capitalization of contract acquisition costs	40,172	29,075
Amortization of deferred contract acquisition costs	(27,341)	(19,817)
Ending balance	$ 72,265	$ 59,434