Estimated Fair Values of Assets Acquired and Liabilities Assumed (Detail) (USD $) In Millions, unless otherwise specified				0 Months Ended	1 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012	Oct. 11, 2013 Plainfield Renewal Energy Holdings LLC	Aug. 31, 2012 maxIT Healthcare Holdings Inc.
Business Combination Allocation of Purchase Price [Line Items]
Cash					$ 9
Receivables				248	50
Other assets				8	24
Accounts payable, accrued liabilities and accrued payroll and employee benefits					(21)
Notes payable assumed (net of debt discount)				(148)
Deferred tax liabilities, net					(24)
Total identifiable net assets acquired				108	38
Goodwill	1,704	1,704	1,309		395
Intangible assets				3	72
Total purchase consideration				$ 111	$ 505