Schedule Of Other Information Related To Acquired Intangibles and Goodwill (Details) - Series of individually immaterial business acquisitions - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill deductible for tax purposes associated with acquisitions	$ 94,318	$ 88,517	$ 165,013
Customer Relationships
Business Acquisition [Line Items]
Amortizable intangible assets acquired, weighted-average estimated useful lives	18 years
Noncompetition agreements
Business Acquisition [Line Items]
Amortizable intangible assets acquired, weighted-average estimated useful lives	5 years	6 years	6 years