DEBT - Additional Information (Detail) (USD $)	0 Months Ended	9 Months Ended
	Jun. 02, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 $1.2 billion senior credit facility weighted average rate 1.61%, due in 2019	Jun. 03, 2014 $1.2 billion senior credit facility weighted average rate 1.61%, due in 2019	Jun. 01, 2014 $1.2 billion senior credit facility weighted average rate 1.61%, due in 2019	Dec. 31, 2013 $1.2 billion senior credit facility weighted average rate 1.61%, due in 2019	Sep. 30, 2014 $100 million private placement notes 5.64%, due in 2015	Sep. 30, 2014 $175 million private placement notes 3.89%, due in 2017	Sep. 30, 2014 $125 million private placement notes 2.68%, due in 2019	Sep. 30, 2014 $225 million private placement notes 4.47%, due in 2020	Sep. 30, 2014 $125 million private placement notes 3.26%, due in 2022	Sep. 30, 2014 Long-term Debt [Member] $100 million private placement notes 5.64%, due in 2015
Debt Instrument [Line Items]
Maximum borrowing capacity of line of credit facility				$ 1,200,000,000.0	$ 1,200,000,000.0	$ 1,000,000,000.0
Long-term debt, face amount								100,000,000.0	175,000,000.0	125,000,000.0	225,000,000.0	125,000,000.0	100,000,000.0
Payment of financing fees	2,100,000	2,280,000	0
Revolving credit facility, amount committed to outstanding letters of credit				187,700,000			155,000,000
Revolving credit facility, unused portion				$ 568,300,000			$ 572,600,000