Goodwill and Other Intangible Assets - Carrying Amount of Other Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	$ 555,682	$ 547,412
Accumulated amortization	(238,251)	(212,828)
Net carrying amount	$ 317,431	$ 334,584
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	14 years	14 years
Gross amount	$ 312,795	$ 312,735
Accumulated amortization	(106,628)	(95,482)
Net carrying amount	206,167	217,253
Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	39,950	39,950
Accumulated amortization	(16,454)	(14,722)
Net carrying amount	$ 23,496	$ 25,228
Trademarks [Member] | Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	10 years	10 years
Trademarks [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	15 years	15 years
Software packages [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	$ 146,398	$ 138,188
Accumulated amortization	(97,265)	(86,605)
Net carrying amount	$ 49,133	$ 51,583
Software packages [Member] | Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	3 years	3 years
Software packages [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	10 years	10 years
Non-compete agreement [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	15 years	15 years
Gross amount	$ 56,539	$ 56,539
Accumulated amortization	(17,904)	(16,019)
Net carrying amount	$ 38,635	$ 40,520