Summary of Significant Accounting Policies - Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Intangible Assets
Gross Carrying Amount	$ 162,656	$ 147,685
Accumulated Amortization	(65,279)	(59,510)
Total intangible assets	97,377	88,175
Non-contractual customer relationships [Member]
Other Intangible Assets
Gross Carrying Amount	116,082	101,056
Accumulated Amortization	(48,821)	(45,295)
Total intangible assets	67,261	55,761
Covenants not-to-compete [Member]
Other Intangible Assets
Gross Carrying Amount	12,435	10,093
Accumulated Amortization	(4,779)	(4,422)
Total intangible assets	7,656	5,671
Favorable lease asset [Member]
Other Intangible Assets
Gross Carrying Amount	9,441	9,576
Accumulated Amortization	(5,440)	(4,962)
Total intangible assets	4,001	4,614
Technology [Member]
Other Intangible Assets
Gross Carrying Amount	1,377	1,627
Accumulated Amortization	(589)	(414)
Total intangible assets	788	1,213
Trademarks [Member]
Other Intangible Assets
Gross Carrying Amount	11,591	13,503
Accumulated Amortization	(4,086)	(4,015)
Total intangible assets	7,505	9,488
Contracts [Member]
Other Intangible Assets
Gross Carrying Amount	0	100
Accumulated Amortization	0	(11)
Total intangible assets	0	89
Franchise rights [Member]
Other Intangible Assets
Gross Carrying Amount	11,730	11,730
Accumulated Amortization	(1,564)	(391)
Total intangible assets	$ 10,166	$ 11,339