SUBSEQUENT EVENT -2014 Debt Refinancing (Details) (Subsequent Event, USD $)	0 Months Ended
	Jul. 02, 2014	Jul. 02, 2014
July 2014 Amendment
Subsequent Event [Line Items]
Additional commitments	$ 200,000,000	$ 200,000,000
Cash balance threshold above which excess amount is not subject to any restriction of use or investment	40,000,000	40,000,000
Line of credit facility outstanding	422,000,000	422,000,000
Weighted average interest rate on debt	1.70%	1.70%
July 2014 Amendment | Maximum
Subsequent Event [Line Items]
Senior credit facility, maximum borrowing capacity		900,000,000
Line of credit, commitment fee percentage	0.30%
Cash borrowed from credit facility	422,000,000
July 2014 Amendment | Maximum | Revolving Credit Facility
Subsequent Event [Line Items]
Senior credit facility, maximum borrowing capacity		750,000,000
Cash borrowed from credit facility	272,000,000
July 2014 Amendment | Maximum | Standby Letters of Credit
Subsequent Event [Line Items]
Senior credit facility, maximum borrowing capacity	60,000,000	60,000,000
July 2014 Amendment | Maximum | Swingline Loan
Subsequent Event [Line Items]
Senior credit facility, maximum borrowing capacity	60,000,000	60,000,000
July 2014 Amendment | Minimum
Subsequent Event [Line Items]
Line of credit, commitment fee percentage	0.15%
June 2011 Amendment | Maximum | Revolving Credit Facility
Subsequent Event [Line Items]
Senior credit facility, maximum borrowing capacity	600,000,000	600,000,000
Term Loan | July 2014 Amendment | Maximum
Subsequent Event [Line Items]
Senior credit facility, maximum borrowing capacity		150,000,000
Cash borrowed from credit facility	$ 150,000,000
Eurodollar | July 2014 Amendment | Maximum
Subsequent Event [Line Items]
Interest rates available to the Company at its option	1.75%
Eurodollar | July 2014 Amendment | Minimum
Subsequent Event [Line Items]
Interest rates available to the Company at its option	1.00%
Federal Funds | July 2014 Amendment
Subsequent Event [Line Items]
Interest rates available to the Company at its option	0.50%
LIBOR | July 2014 Amendment
Subsequent Event [Line Items]
Interest rates available to the Company at its option	1.00%