Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Intangible Assets [Line Items]
Amortization of intangible assets	$ 8,464	$ 10,144
Intangible assets subject to amortization:
Gross Carrying Amount	296,723		$ 296,586
Accumulated Amortization	172,949		164,373
Net Carrying Amount	123,774		132,213
Intangible assets not subject to amortization:
Trademarks, Carrying Amount	245,565		245,517
Goodwill, Carrying Amount	873,872		873,513
Intangible Assets, Gross (Excluding Goodwill)	542,288		542,103
Total
Identifiable intangible assets, net	369,339		377,730
Customer relations
Intangible assets subject to amortization:
Gross Carrying Amount	196,318		196,204
Accumulated Amortization	103,708		98,804
Net Carrying Amount	$ 92,610		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	$ 69,739		69,721
Accumulated Amortization	52,971		50,528
Net Carrying Amount	$ 16,768		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	$ 10,866		10,861
Accumulated Amortization	5,308		4,922
Net Carrying Amount	$ 5,558		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
Accumulated Amortization	10,454		9,666
Net Carrying Amount	$ 8,446		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
Accumulated Amortization	508		453
Net Carrying Amount	$ 392		$ 447