Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended			9 Months Ended
	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Subsequent Event [Line Items]
Repayments of Unsecured Debt	$ 7,100	$ 500,000				$ 759,948	$ 1,556
Gains (Losses) on Extinguishment of Debt				$ 64	$ 0	$ (82,589)	$ (139)
Declaration of Dividends [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Common stock dividends declared per share			$ 0.18
Record date			Nov. 16, 2015
Payment date			Nov. 30, 2015
Debt Repayment [Member]
Subsequent Event [Line Items]
Repayments of Unsecured Debt			$ 150,000
Gains (Losses) on Extinguishment of Debt			$ 3,100
Special Dividend [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Payment date			Dec. 15, 2015
Special Dividend [Member] | Declaration of Dividends [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Common stock dividends declared per share			$ 0.20