Amortizable Intangible Assets - Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 1,413,494	$ 1,384,689
Accumulated Amortization	(641,414)	(600,047)
Net Carrying Value	772,080	784,642
Purchased customer accounts
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,384,195	1,355,550
Accumulated Amortization	(615,046)	(574,285)
Net Carrying Value	$ 769,149	$ 781,265
Weighted Average Life (Years)	15 years	14 years 10 months 24 days
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 29,299	$ 29,139
Accumulated Amortization	(26,368)	(25,762)
Net Carrying Value	$ 2,931	$ 3,377
Weighted Average Life (Years)	6 years 9 months 18 days	6 years 9 months 18 days