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Business Combinations - Acquisition of Gila LLC and Xtend Healthcare - Additional Information (Detail) - USD ($) $ in Millions		1 Months Ended		9 Months Ended
	Sep. 30, 2016	Oct. 31, 2015	Feb. 28, 2015	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015
Asset Recovery - Gila LLC [Member]
Indefinite-lived Intangible Assets [Line Items]
Business acquisition, effective date of acquisition				Feb. 28, 2015
Controlling interest percentage			98.00%
Business acquisition, purchase price			$ 185
Goodwill						$ 97
Business acquisition, indefinite life intangible asset						13
Business acquisition, definite life intangible assets						$ 71
Asset Recovery - Gila LLC [Member] | Minimum [Member]
Indefinite-lived Intangible Assets [Line Items]
Definite life intangible assets, amortization period	2 years
Asset Recovery - Gila LLC [Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Definite life intangible assets, amortization period	16 years
Asset Recovery - Xtend Healthcare [Member]
Indefinite-lived Intangible Assets [Line Items]
Business acquisition, effective date of acquisition				Oct. 31, 2015
Controlling interest percentage		89.00%
Business acquisition, purchase price		$ 164
Goodwill					$ 102
Business acquisition, definite life intangible assets					$ 65
Asset Recovery - Xtend Healthcare [Member] | Minimum [Member]
Indefinite-lived Intangible Assets [Line Items]
Definite life intangible assets, amortization period				10 years
Asset Recovery - Xtend Healthcare [Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Definite life intangible assets, amortization period				15 years

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Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

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