Revenue from Contracts with Customers - Summary of Contract Asset Account (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Contract With Customer Asset And Liability [Abstract]
Balance, beginning of period	$ 51,499	$ 50,091	$ 51,701	$ 50,119
Current period sales, net of collection of renewal commissions	1,024	376	822	348
Balance, at the end of period	$ 52,523	$ 50,467	$ 52,523	$ 50,467