Revenue Recognition (Schedule Of Disaggregated Revenue) (Details) - Roto-Rooter [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Subtotal	$ 159,825	$ 144,035	$ 479,733	$ 439,760
Implicit price concessions and credit memos	(960)	(1,648)	(4,781)	(5,197)
Net revenue	158,865	142,387	474,952	434,563
Short-Term Core Service Jobs [Member]
Subtotal	115,135	102,346	341,337	311,518
Water Restoration [Member]
Subtotal	25,738	25,001	81,629	77,502
Contractor Revenue [Member]
Subtotal	14,342	12,219	42,931	36,950
Franchise Fees [Member]
Subtotal	1,819	1,593	5,063	4,758
Other [Member]
Subtotal	$ 2,791	$ 2,876	$ 8,773	$ 9,032