Revenue Recognition - Graduation Fund (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Graduation Fund [Roll Forward]
Balance at beginning of period	$ 46,842	$ 52,024
Revenue deferred	4,652	4,368
Benefit redeemed	(5,574)	(5,182)
Balance at end of period	$ 45,920	$ 51,210