Revenue Recognition (Schedule Of Disaggregated Revenue) (Details) - Roto-Rooter [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Subtotal	$ 162,559	$ 146,626	$ 319,908	$ 295,725
Implicit price concessions and credit memos	(1,725)	(1,612)	(3,821)	(3,549)
Net revenue	160,834	145,014	316,087	292,176
Short-Term Core Service Jobs [Member]
Subtotal	115,143	105,086	226,202	209,172
Water Restoration [Member]
Subtotal	28,239	24,765	55,891	52,502
Contractor Revenue [Member]
Subtotal	14,580	12,366	28,589	24,731
Franchise Fees [Member]
Subtotal	1,623	1,574	3,245	3,165
Other [Member]
Subtotal	$ 2,974	$ 2,835	$ 5,981	$ 6,155