Description of Business and Summary of Significant Accounting Policies Description of Business and Summary of Significant Accounting Policies - Advertising (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Capitalized Direct Response Advertising Costs [Line Items]
Advertising expense	$ 9,700	$ 7,500	$ 6,100
Capital direct response advertising, amortization			3,900
Capitalized direct response advertising costs, net			$ 1,900
ASC 340-40
Capitalized Direct Response Advertising Costs [Line Items]
New accounting pronouncement or change in account principle, effect of amortization period adjustment to production costs		1,900
New accounting pronouncement or change in accounting principle, effect of change on net income		$ 522