Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019		Dec. 31, 2018
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amounts	$ 3,482,233		$ 3,367,524
Accumulated Amortization	(1,065,045)		(959,614)
Net Carrying Amount	2,417,188	[1]	2,407,910
Trade names and trademarks—indefinite lived
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amounts	481,741		479,555
Accumulated Amortization	0		0
Net Carrying Amount	$ 481,741		479,555
Customer and vendor relationships
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted- Avg Useful Lives (Years)	16 years 9 months 18 days
Gross Carrying Amounts	$ 2,732,332		2,625,270
Accumulated Amortization	(863,392)		(776,383)
Net Carrying Amount	$ 1,868,940		1,848,887
Trade names and trademarks—other
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted- Avg Useful Lives (Years)	14 years 4 months 24 days
Gross Carrying Amounts	$ 4,949		2,957
Accumulated Amortization	(2,641)		(2,501)
Net Carrying Amount	$ 2,308		456
Software
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted- Avg Useful Lives (Years)	5 years 10 months 24 days
Gross Carrying Amounts	$ 214,272		212,733
Accumulated Amortization	(166,505)		(152,416)
Net Carrying Amount	$ 47,767		60,317
Non-compete agreements
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted- Avg Useful Lives (Years)	4 years 1 month 6 days
Gross Carrying Amounts	$ 48,939		47,009
Accumulated Amortization	(32,507)		(28,314)
Net Carrying Amount	$ 16,432		$ 18,695

[1] Reflects the impact of the Company's adoption of ASU 2016-02 "Leases", on January 1, 2019, using a modified retrospective transition method. Under this method, financial results reported in periods prior to 2019 are unchanged. Refer to footnote 2.