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Business Combinations - Acquisition of Gila LLC and Xtend Healthcare - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended		6 Months Ended	9 Months Ended
	Oct. 31, 2015	Feb. 28, 2015	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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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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