The preliminary values of major classes of assets acquired and liabilities assumed recorded at the date of acquisition, as adjusted during the valuation period (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Materials & supplies	$ 17,579,000	$ 15,788,000
Goodwill	563,075,000	$ 368,481,000
Finite-lived Intangible Assets Acquired	397,523,000
Customer Contracts [Member]
Restructuring Cost and Reserve [Line Items]
Finite-lived Intangible Assets Acquired	$ 283,309,000
Customer Contracts [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Finite lived intangible assets useful life	3 years
Customer Contracts [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Finite lived intangible assets useful life	12 years
Trademarks and Trade Names [Member]
Restructuring Cost and Reserve [Line Items]
Finite-lived Intangible Assets Acquired	$ 102,986,000
Trademarks and Trade Names [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Finite lived intangible assets useful life	20 years
Noncompete Agreements [Member]
Restructuring Cost and Reserve [Line Items]
Finite-lived Intangible Assets Acquired	$ 4,881,000
Noncompete Agreements [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Finite lived intangible assets useful life	3 years
Noncompete Agreements [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Finite lived intangible assets useful life	20 years
Patents [Member]
Restructuring Cost and Reserve [Line Items]
Finite-lived Intangible Assets Acquired	$ 1,743,000
Patents [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Finite lived intangible assets useful life	3 years
Patents [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Finite lived intangible assets useful life	15 years
Other Intangible Assets [Member]
Restructuring Cost and Reserve [Line Items]
Finite-lived Intangible Assets Acquired	$ 2,377,000
Finite lived intangible assets useful life	10 years
Internet Domain Names [Member]
Restructuring Cost and Reserve [Line Items]
Finite-lived Intangible Assets Acquired	$ 2,227,000
Acquisitions [Member]
Restructuring Cost and Reserve [Line Items]
Accounts receivable, net	7,496,000
Materials & supplies	1,213,000
Equipment and property	67,048,000
Goodwill	194,562,000
Customer contracts and other intangible assets	173,450,000
Current liabilities	(13,470,000)
Other assets and liabilities, net	(7,532)
Total cash purchase price	422,767,000
Less: Contingent consideration liability	(12,700,000)
Total cash purchase price	$ 410,067