Revenue Recognition (Schedule Of Disaggregated Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Subtotal	$ 306,791	$ 323,197
Net revenue	299,189	315,788
Roto-Rooter [Member]
Subtotal	236,998	216,817
Implicit price concessions and credit memos	(5,638)	(5,245)
Net revenue	231,360	211,572
Roto-Rooter [Member] | Short-Term Core Service Jobs [Member]
Subtotal	169,712	155,350
Roto-Rooter [Member] | Water Restoration [Member]
Subtotal	40,360	37,435
Roto-Rooter [Member] | Independent Contractors [Member]
Subtotal	21,418	18,760
Roto-Rooter [Member] | Franchise Fees [Member]
Subtotal	1,317	1,327
Roto-Rooter [Member] | All Other [Member]
Subtotal	$ 4,191	$ 3,945