Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Intangible Assets [Line Items]
Amortization of intangible assets	$ 8,299	$ 10,032	$ 16,763	$ 20,176
Intangible assets subject to amortization:
Gross Carrying Amount	297,339		297,339		$ 296,586
Accumulated Amortization	181,579		181,579		164,373
Net Carrying Amount	115,760		115,760		132,213
Intangible assets not subject to amortization:
Trademarks, Carrying Amount	245,780		245,780		245,517
Goodwill, Carrying Amount	875,431		875,431		873,513
Intangible Assets, Gross (Excluding Goodwill)	543,119		543,119		542,103
Total
Identifiable intangible assets, net	361,540		361,540		377,730
Customer relations
Intangible assets subject to amortization:
Gross Carrying Amount	196,827		196,827		196,204
Accumulated Amortization	108,872		108,872		98,804
Net Carrying Amount	87,955		$ 87,955		97,400
Customer relations | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			2 years
Customer relations | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			10 years
Contractor Relations [Member]
Intangible assets subject to amortization:
Gross Carrying Amount	69,820		$ 69,820		69,721
Accumulated Amortization	55,191		55,191		50,528
Net Carrying Amount	14,629		$ 14,629		19,193
Contractor Relations [Member] | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			2 years
Contractor Relations [Member] | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			5 years
Non-compete agreements
Intangible assets subject to amortization:
Gross Carrying Amount	10,892		$ 10,892		10,861
Accumulated Amortization	5,712		5,712		4,922
Net Carrying Amount	5,180		$ 5,180		5,939
Non-compete agreements | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			2 years
Non-compete agreements | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			7 years
Computer Software, Intangible Asset [Member]
Intangible Assets [Line Items]
Estimated Useful Life			6 years
Intangible assets subject to amortization:
Gross Carrying Amount	18,900		$ 18,900		18,900
Accumulated Amortization	11,241		11,241		9,666
Net Carrying Amount	7,659		$ 7,659		9,234
Contract-Based Intangible Assets [Member]
Intangible Assets [Line Items]
Estimated Useful Life			5 years
Intangible assets subject to amortization:
Gross Carrying Amount	900		$ 900		900
Accumulated Amortization	563		563		453
Net Carrying Amount	$ 337		$ 337		$ 447