Summary of Significant Accounting Policies - Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Other Intangible Assets
Gross Carrying Amount	$ 295,549	$ 162,656
Accumulated Amortization	(87,012)	(65,279)
Total finite-lived intangibles, net	208,537	97,377
Non-contractual customer relationships
Other Intangible Assets
Gross Carrying Amount	218,847	116,082
Accumulated Amortization	(62,331)	(48,821)
Total finite-lived intangibles, net	156,516	67,261
Covenants not-to-compete
Other Intangible Assets
Gross Carrying Amount	23,990	12,435
Accumulated Amortization	(7,580)	(4,779)
Total finite-lived intangibles, net	16,410	7,656
Favorable lease assets
Other Intangible Assets
Gross Carrying Amount	9,451	9,441
Accumulated Amortization	(5,855)	(5,440)
Total finite-lived intangibles, net	3,596	4,001
Technology
Other Intangible Assets
Gross Carrying Amount	1,377	1,377
Accumulated Amortization	(795)	(589)
Total finite-lived intangibles, net	582	788
Trademarks
Other Intangible Assets
Gross Carrying Amount	30,144	11,591
Accumulated Amortization	(7,713)	(4,086)
Total finite-lived intangibles, net	22,431	7,505
Client lists
Other Intangible Assets
Gross Carrying Amount	10	0
Accumulated Amortization	(1)	0
Total finite-lived intangibles, net	9	0
Franchise rights
Other Intangible Assets
Gross Carrying Amount	11,730	11,730
Accumulated Amortization	(2,737)	(1,564)
Total finite-lived intangibles, net	$ 8,993	$ 10,166