Treasury - Additional Information (Detail)			1 Months Ended	3 Months Ended						9 Months Ended	12 Months Ended
	Jun. 07, 2016 USD ($)	May 31, 2015 USD ($) Derivative	Apr. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2015 USD ($) Derivative	Sep. 30, 2015 USD ($) Derivative	Jun. 30, 2015 USD ($) Derivative	Dec. 31, 2014 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2015 USD ($) Derivative	Dec. 31, 2017 USD ($)	Jun. 03, 2016 USD ($)	Aug. 07, 2014 USD ($)
Equity Class Of Treasury Stock [Line Items]
Line of credit facility, starting date	Jun. 07, 2016
Line of credit facility, maturity month	2019-08
Rate adjustment to weighted average federal funds rate for credit facility borrowings				0.50%
Rate adjustment to one month Eurodollar rate on credit facility borrowings				1.00%
Accounts receivable securitization program credit facility, borrowing capacity				$ 440,000,000
Accounts receivable securitization program credit facility, amount outstanding				440,000,000
Accounts receivable securitization program credit facility, available borrowing capacity				0
Debt instrument carrying amount				3,900,000,000								$ 4,000,000,000
Fair value of debt				3,900,000,000								4,100,000,000
Number of additional forward starting interest rate swaps | Derivative							4
Previously Outstanding Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Maturity date of interest rate cash flow hedges		May 31, 2015
One Point Three One Percent Forward Starting Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Maturity date of interest rate cash flow hedges											Apr. 15, 2019
Number of additional forward starting interest rate swaps | Derivative											9
Fixed rate payable on interest rate swap						1.31%					1.31%
One Point Four Zero Percent Forward Starting Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Maturity date of interest rate cash flow hedges								Apr. 15, 2019
Number of additional forward starting interest rate swaps | Derivative								4
Average fixed rate payable on interest rate swap								1.40%
One Point Two Three Percent Forward Starting Interest Rate Swaps One
Equity Class Of Treasury Stock [Line Items]
Maturity date of interest rate cash flow hedges							Apr. 15, 2019
Average fixed rate payable on interest rate swap							1.23%
One Point Two One Percent Forward Starting Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Maturity date of interest rate cash flow hedges						Apr. 15, 2019
Number of additional forward starting interest rate swaps | Derivative						1
Fixed rate payable on interest rate swap						1.21%					1.21%
Interest Rate Swap
Equity Class Of Treasury Stock [Line Items]
Fair value of our interest rate swaps				9,000,000								7,000,000
Interest Rate Swap | Net Accounts Receivable
Equity Class Of Treasury Stock [Line Items]
Fair value of our interest rate swaps, assets				8,000,000								4,000,000
Interest Rate Swap | Other Assets
Equity Class Of Treasury Stock [Line Items]
Fair value of our interest rate swaps, assets				1,000,000								$ 3,000,000
Foreign Currency Forward Exchange Contracts
Equity Class Of Treasury Stock [Line Items]
Net cash outflows				(46,000,000)	$ (8,000,000)
Cash Flow Hedging | Previously Outstanding Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Number of interest rate swaps | Derivative		7
Notional amount of interest rate cash flow hedges		$ 825,000,000
Cash Flow Hedging | One Point Three One Percent Forward Starting Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Notional amount of interest rate cash flow hedges						$ 1,000,000,000					$ 1,000,000,000
Cash Flow Hedging | One Point Four Zero Percent Forward Starting Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Notional amount of interest rate cash flow hedges								$ 500,000,000
Cash Flow Hedging | Forward Starting Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Notional amount of interest rate cash flow hedges							$ 400,000,000
Cash Flow Hedging | One Point Two Three Percent Forward Starting Interest Rate Swaps One
Equity Class Of Treasury Stock [Line Items]
Notional amount of interest rate cash flow hedges							100,000,000
Cash Flow Hedging | One Point Two Three Percent Forward Starting Interest Rate Swaps Two
Equity Class Of Treasury Stock [Line Items]
Notional amount of interest rate cash flow hedges							200,000,000
Cash Flow Hedging | One Point Two Three Percent Forward Starting Interest Rate Swaps Three
Equity Class Of Treasury Stock [Line Items]
Notional amount of interest rate cash flow hedges							$ 100,000,000
Cash Flow Hedging | One Point Two One Percent Forward Starting Interest Rate Swaps
Equity Class Of Treasury Stock [Line Items]
Notional amount of interest rate cash flow hedges						$ 100,000,000					$ 100,000,000
Subsequent Event
Equity Class Of Treasury Stock [Line Items]
Line of credit facility increased amount			$ 10,000,000
Accounts receivable securitization program credit facility, borrowing capacity			$ 450,000,000
Revolving Credit Facility
Equity Class Of Treasury Stock [Line Items]
Line of credit facility, borrowing capacity	$ 800,000,000			800,000,000
Line of credit facility amount outstanding				$ 285,000,000
Current applicable margins				1.50%
Line of credit facility, available borrowing capacity				$ 446,000,000
Letters of credit, outstanding				34,000,000
Revolving Credit Facility | Short Term on Demand Credit Facility
Equity Class Of Treasury Stock [Line Items]
Line of credit facility amount outstanding				35,000,000
Revolving Credit Facility | Letter of Credit
Equity Class Of Treasury Stock [Line Items]
Line of credit facility, borrowing capacity				$ 125,000,000
Revolving Credit Facility | ABR-based loans
Equity Class Of Treasury Stock [Line Items]
Current applicable margins				0.50%
Revolving Credit Facility | Minimum | One Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				0.50%
Revolving Credit Facility | Minimum | One Two Three Six Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				1.50%
Revolving Credit Facility | Maximum | One Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				1.25%
Revolving Credit Facility | Maximum | One Two Three Six Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				2.25%
Term Loan A
Equity Class Of Treasury Stock [Line Items]
Line of credit facility amount outstanding				$ 1,753,000,000
Line of credit facility increased amount	$ 200,000,000
Current applicable margins				1.50%
Term Loan A | Quarterly installment payments made from the fourth quarter of 2014 through third quarter of 2016
Equity Class Of Treasury Stock [Line Items]
Scheduled principal payments made									$ 11,000,000
Term Loan A | Quarterly installment payments after September, 2016
Equity Class Of Treasury Stock [Line Items]
Scheduled principal payments made										$ 22,000,000
Term Loan A | ABR-based loans
Equity Class Of Treasury Stock [Line Items]
Current applicable margins				0.50%
Term Loan A | Minimum | One Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				0.50%
Term Loan A | Minimum | One Two Three Six Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				1.50%
Term Loan A | Maximum | One Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				1.25%
Term Loan A | Maximum | One Two Three Six Month Eurodollar Rate Plus Index Based Loans
Equity Class Of Treasury Stock [Line Items]
Consolidated Leverage Ratio				2.25%
New Senior Secured Notes
Equity Class Of Treasury Stock [Line Items]
Senior notes, issued				$ 1,400,000,000
New Senior Secured Notes | 3.75% Senior Secured Notes due 2019
Equity Class Of Treasury Stock [Line Items]
Senior notes, issued														$ 300,000,000
Senior notes, interest rate														3.75%
Senior notes, maturity date				Aug. 01, 2019
New Senior Secured Notes | 4.75% Senior Secured Notes due 2022
Equity Class Of Treasury Stock [Line Items]
Senior notes, issued				$ 700,000,000									$ 400,000,000	$ 300,000,000
Senior notes, interest rate				4.75%
Senior notes issued percentage													101.50%
Senior notes yield percentage													4.35%
Senior notes, maturity date				Aug. 01, 2022
New Senior Secured Notes | 5.00% Senior Secured Notes due 2026
Equity Class Of Treasury Stock [Line Items]
Senior notes, issued													$ 400,000,000
Senior notes, interest rate													5.00%
Senior notes, maturity date				Jun. 01, 2026