Revenue - Contract Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Change in Contract with Customer, Asset [Abstract]
Balance at December 31, 2020	$ 3,529
Estimated lifetime value of insurance policies sold by carriers	5,488
Cash receipts	(1,580)
Balance at September 30, 2021	7,437
Contract assets	7,437
Long-term accounts receivable	7,159
Accounts Receivable Current
Change in Contract with Customer, Asset [Abstract]
Balance at September 30, 2021	278
Contract assets	$ 278