Consolidated Statements of Cash Flows (Parenthetical)	12 Months Ended
	Sep. 30, 2017
Series A Preferred Stock [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Preferred Stock, Dividend Rate, Percentage	7.625%
Series B Preferred Stock [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Preferred Stock, Dividend Rate, Percentage	7.875%
Series C Preferred Stock [Member] | At The Market Offerings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Preferred Stock, Dividend Rate, Percentage	6.125%