Acquisitions, Goodwill and Other Intangible Assets - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired	$ 1,244,603	$ 24,971	$ 179,481
Identifiable assets acquired and liabilities assumed:
Goodwill	1,520,575	$ 1,243,034	$ 1,221,400
2021 Acquisitions
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired	1,284,000
Shares transferred	181,700
Estimated fair value of contingent consideration	101,600
Total consideration transferred	1,567,300
Identifiable assets acquired and liabilities assumed:
Accounts receivable and contract assets	683,700
Current assets	42,200
Property and equipment	498,100
Long-term assets, primarily operating lease right-of-use assets	170,900
Amortizing intangible assets	563,100
Accounts payable	(174,700)
Current liabilities, including current portion of operating lease liabilities	(269,000)
Long-term debt, including finance lease obligations	(5,100)
Long-term debt, including finance lease obligations	(215,700)
Total identifiable net assets	1,293,500
Goodwill	277,300
Total net assets acquired, including goodwill	1,570,800
Bargain purchase gain	(3,500)
Acquisition consideration outstanding	40,000
HMG
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired	416,900
Shares transferred	181,700
Estimated fair value of contingent consideration	0
Total consideration transferred	598,600
Identifiable assets acquired and liabilities assumed:
Accounts receivable and contract assets	414,300
Current assets	14,600
Property and equipment	247,000
Long-term assets, primarily operating lease right-of-use assets	85,100
Amortizing intangible assets	112,000
Accounts payable	(125,400)
Current liabilities, including current portion of operating lease liabilities	(132,200)
Long-term debt, including finance lease obligations	0
Long-term debt, including finance lease obligations	(137,600)
Total identifiable net assets	477,800
Goodwill	120,800
Total net assets acquired, including goodwill	598,600
Bargain purchase gain	0
All other
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired	867,100
Shares transferred	0
Estimated fair value of contingent consideration	101,600
Total consideration transferred	968,700
Identifiable assets acquired and liabilities assumed:
Accounts receivable and contract assets	269,400
Current assets	27,600
Property and equipment	251,100
Long-term assets, primarily operating lease right-of-use assets	85,800
Amortizing intangible assets	451,100
Accounts payable	(49,300)
Current liabilities, including current portion of operating lease liabilities	(136,800)
Long-term debt, including finance lease obligations	(5,100)
Long-term debt, including finance lease obligations	(78,100)
Total identifiable net assets	815,700
Goodwill	156,500
Total net assets acquired, including goodwill	972,200
Bargain purchase gain	$ (3,500)