Allowance for Expected Credit Losses Balances of Premiums Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Balance, beginning of period	$ 179,147	$ 193,369
Balance, end of period	170,953	179,147
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	1,754	578
Current period change for expected credit losses	2,339	3,294
Writeoffs of uncollectable accounts receivable	(2,285)	(2,118)
Balance, end of period	$ 1,808	$ 1,754