EQUITY - Issuance and Redemption of Preferred Shares (Details)	3 Months Ended
	Oct. 31, 2017 shares
Series C Preferred Stock [Member]
Issuance of Series C Preferred Shares and Redemption of Series B Preferred Shares
Preferred shares issued (in shares)	4,118,460
Distribution rate percentage (in hundredths)	6.625%
Series B Preferred Stock [Member]
Issuance of Series C Preferred Shares and Redemption of Series B Preferred Shares
Stock Redeemed or Called During Period, Shares	4,600,000
Distribution rate percentage (in hundredths)	7.95%