Goodwill and Identifiable Assets Acquired Intangible Assets (Details) - USD ($) $ in Thousands		12 Months Ended
	Apr. 02, 2018	Dec. 31, 2018	Dec. 31, 2017
Intangible Assets [Line Items]
Identifiable intangible assets, net		$ 488,691	$ 352,766
Intangible Assets, Gross (Excluding Goodwill)		745,653	551,301
Intangible assets subject to amortization:
Gross Carrying Amount		483,431	305,359
Accumulated Amortization		256,962	198,535
Net Carrying Amount		226,469	106,824
Intangible assets not subject to amortization:
Trademarks, Carrying Amount		262,222	245,942
Contractual customer relationships
Intangible Assets [Line Items]
Estimated Useful Life	12 years 9 months
Intangible assets subject to amortization:
Gross Carrying Amount		346,799	202,588
Accumulated Amortization		145,424	119,272
Net Carrying Amount		$ 201,375	83,316
Contractual customer relationships | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life		2 months
Contractual customer relationships | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life		12 years 9 months
Contractor relations
Intangible assets subject to amortization:
Gross Carrying Amount		$ 71,104	71,121
Accumulated Amortization		67,072	59,174
Net Carrying Amount		$ 4,032	11,947
Contractor relations | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life		2 years
Contractor relations | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life		5 years
Backlog
Intangible Assets [Line Items]
Estimated Useful Life	2 years 9 months
Intangible assets subject to amortization:
Gross Carrying Amount		$ 23,100
Accumulated Amortization		17,740
Net Carrying Amount		$ 5,360
Backlog | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life		2 years 9 months
Non-compete agreements
Intangible assets subject to amortization:
Gross Carrying Amount		$ 22,128	11,850
Accumulated Amortization		9,907	6,600
Net Carrying Amount		$ 12,221	5,250
Non-compete agreements | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life	4 years	2 years
Non-compete agreements | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life	7 years	7 years
In-use software
Intangible assets subject to amortization:
Gross Carrying Amount		$ 18,900	18,900
Accumulated Amortization		15,966	12,816
Net Carrying Amount		$ 2,934	6,084
In-use software | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life		6 years
Favorable contracts
Intangible Assets [Line Items]
Estimated Useful Life	5 years
Intangible assets subject to amortization:
Gross Carrying Amount		$ 1,400	900
Accumulated Amortization		853	673
Net Carrying Amount		$ 547	$ 227
Favorable contracts | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life		5 years