Acquisitions & Dispositions - Summary of Purchased Identifiable Intangible Assets (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
CPO [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	$ 12,800
MEDCO [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	40,000
NESTOR [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	16,930
Customer relationships [Member] | CPO [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	$ 5,200
Finite lived intangible assets estimated life	3 years
Customer relationships [Member] | MEDCO [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	$ 37,590
Customer relationships [Member] | MEDCO [Member] | Minimum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets estimated life	3 years
Customer relationships [Member] | MEDCO [Member] | Maximum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets estimated life	15 years
Customer relationships [Member] | NESTOR [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	$ 15,570
Finite lived intangible assets estimated life	13 years
Trademarks [Member] | CPO [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	$ 7,600
Finite lived intangible assets estimated life	15 years
Trademarks [Member] | MEDCO [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	$ 2,410
Trademarks [Member] | MEDCO [Member] | Minimum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets estimated life	1 year 6 months
Trademarks [Member] | MEDCO [Member] | Maximum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets estimated life	15 years
Trademarks [Member] | NESTOR [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets	$ 1,360
Trademarks [Member] | NESTOR [Member] | Minimum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets estimated life	2 years 6 months
Trademarks [Member] | NESTOR [Member] | Maximum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets estimated life	15 years