SUBSEQUENT EVENT (Details) (USD $)	6 Months Ended	1 Months Ended
	Dec. 31, 2011	Jan. 31, 2012 Common Stock Offering	Feb. 29, 2012 Debt Repayment	Feb. 02, 2012 Debt Repayment
Subsequent Event
Shares sold		4,000,000
Sale price per share (in dollars per share)		$ 67.10
Proceeds from shares sold	$ 2,917,000	$ 268,400,000
Repayments under revolving credit facility			170,000,000
Amount available under revolving credit facility				$ 225,000,000