Acquisitions, Goodwill and Other Intangible Assets - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired	$ 44,908	$ 589,055
Identifiable assets acquired and liabilities assumed:
Goodwill	$ 1,484,600		$ 1,520,575
2021 Acquisitions
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired			1,269,700
Shares transferred			181,700
Estimated fair value of contingent consideration			103,000
Total consideration			1,554,300
Identifiable assets acquired and liabilities assumed:
Accounts receivable and contract assets			680,700
Current assets			41,300
Property and equipment			503,000
Long-term assets, primarily operating lease right-of-use assets			166,900
Amortizing intangible assets			608,800
Accounts payable			(157,300)
Current liabilities, including current portion of operating lease liabilities			(287,900)
Long-term debt, including finance lease obligations			(4,600)
Long-term liabilities, primarily operating lease liabilities and deferred income taxes			(227,500)
Total identifiable net assets			1,323,400
Goodwill			234,500
Total net assets acquired, including goodwill			1,557,900
Bargain purchase gain			(3,600)
Total consideration			1,554,300
2021 Acquisitions | Contingent Consideration
Business Combination, Consideration Transferred [Abstract]
Estimated fair value of contingent consideration			102,900
HMG
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired			402,400
Shares transferred			181,700
Total consideration			584,100
Identifiable assets acquired and liabilities assumed:
Accounts receivable and contract assets			409,500
Current assets			14,600
Property and equipment			252,400
Long-term assets, primarily operating lease right-of-use assets			85,100
Amortizing intangible assets			164,600
Accounts payable			(108,000)
Current liabilities, including current portion of operating lease liabilities			(151,200)
Long-term debt, including finance lease obligations			(200)
Long-term liabilities, primarily operating lease liabilities and deferred income taxes			(151,000)
Total identifiable net assets			515,800
Goodwill			68,300
Total net assets acquired, including goodwill			584,100
Bargain purchase gain			0
Total consideration			584,100
HMG | Contingent Consideration
Business Combination, Consideration Transferred [Abstract]
Estimated fair value of contingent consideration			0
All other
Business Combination, Consideration Transferred [Abstract]
Cash, net of cash acquired			867,300
Shares transferred			0
Total consideration			970,200
Identifiable assets acquired and liabilities assumed:
Accounts receivable and contract assets			271,200
Current assets			26,700
Property and equipment			250,600
Long-term assets, primarily operating lease right-of-use assets			81,800
Amortizing intangible assets			444,200
Accounts payable			(49,300)
Current liabilities, including current portion of operating lease liabilities			(136,700)
Long-term debt, including finance lease obligations			(4,400)
Long-term liabilities, primarily operating lease liabilities and deferred income taxes			(76,500)
Total identifiable net assets			807,600
Goodwill			166,200
Total net assets acquired, including goodwill			973,800
Bargain purchase gain			(3,600)
Total consideration			970,200
All other | Contingent Consideration
Business Combination, Consideration Transferred [Abstract]
Estimated fair value of contingent consideration			$ 102,900