DEBT - Additional Information (Detail) - USD ($)			1 Months Ended
	Aug. 21, 2015	Apr. 30, 2015	Apr. 30, 2015	Sep. 30, 2015	Dec. 31, 2014
$1.2 billion senior credit facility weighted average rate 1.51%, due in 2019
Debt Instrument [Line Items]
Maximum borrowing capacity of line of credit facility				$ 1,200,000,000.0
Revolving credit facility, amount committed to outstanding letters of credit				149,200,000	$ 162,900,000
Revolving credit facility, unused portion				874,400,000	$ 577,100,000
$100 million private placement notes 5.64%, due in 2015 | Long-term Debt [Member]
Debt Instrument [Line Items]
Repayments of Debt			$ 100,000,000
$175 million private placement notes 3.89%, due in 2017
Debt Instrument [Line Items]
Long-term debt, face amount				$ 175,000,000.0
Stated interest rate				3.89%
$125 million private placement notes 2.68%, due in 2019
Debt Instrument [Line Items]
Long-term debt, face amount				$ 125,000,000.0
Stated interest rate				2.68%
$225 million private placement notes 4.47%, due in 2020
Debt Instrument [Line Items]
Long-term debt, face amount				$ 225,000,000.0
Stated interest rate				4.47%
$125 million private placement notes 3.26%, due in 2022
Debt Instrument [Line Items]
Long-term debt, face amount				$ 125,000,000.0
Stated interest rate				3.26%
$200 million private placement notes 2.72%, due in 2022
Debt Instrument [Line Items]
Long-term debt, face amount				$ 200,000,000
Stated interest rate				2.72%
$100 million private placement notes 2.79%, due in 2023
Debt Instrument [Line Items]
Long-term debt, face amount				$ 100,000,000
Stated interest rate				2.79%
Senior Notes | Senior Notes 2.67% Series A
Debt Instrument [Line Items]
Long-term debt, face amount		$ 200,000,000	$ 200,000,000
Debt instrument, term		7 years
Stated interest rate		2.72%	2.72%
Senior Notes | Senior Notes 2.74% Series B
Debt Instrument [Line Items]
Long-term debt, face amount		$ 100,000,000	$ 100,000,000
Debt instrument, term		8 years
Stated interest rate		2.79%	2.79%
$1.5 billion term loan facility, due in 2020
Debt Instrument [Line Items]
Maximum borrowing capacity of line of credit facility				$ 1,500,000,000.0
$1.5 billion term loan facility, due in 2020 | Federal Funds Rate
Debt Instrument [Line Items]
Spread on variable rate	0.50%
$1.5 billion term loan facility, due in 2020 | Eurodollar Rate
Debt Instrument [Line Items]
Spread on variable rate	1.00%
Minimum | $1.5 billion term loan facility, due in 2020 | Eurodollar Rate
Debt Instrument [Line Items]
Spread on variable rate	1.00%
Minimum | $1.5 billion term loan facility, due in 2020 | Base Rate
Debt Instrument [Line Items]
Spread on variable rate	0.00%
Maximum | $1.5 billion term loan facility, due in 2020 | Eurodollar Rate
Debt Instrument [Line Items]
Spread on variable rate	2.00%
Maximum | $1.5 billion term loan facility, due in 2020 | Base Rate
Debt Instrument [Line Items]
Spread on variable rate	1.00%