Schedule II - Valuation and Qualifying Accounts and Reserves - Valuation Allowances and Reserves (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for Insurance and Claims Accruals [Member]
Balance at Beginning of Year		$ 31,729	$ 28,103	$ 26,177
Charged to Costs and Expenses		64,276	56,075	56,122
Deductions	[1]	(56,410)	(52,449)	(54,196)
Balance at End of Year		39,595	31,729	28,103
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Balance at Beginning of Year		382	348	300
Charged to Costs and Expenses		220	65	163
Deductions	[2]	(254)	(31)	(115)
Balance at End of Year		$ 348	$ 382	$ 348

[1] Claims payments

[2] Write-off of bad debts, net of recoveries