Subsequent Events (Details) - Rochester Portfolio - USD ($)	1 Months Ended	3 Months Ended
	May. 31, 2014	Sep. 30, 2015	Jul. 24, 2015	Jun. 30, 2015	Dec. 31, 2014	Jan. 31, 2013
Subsequent Events
Gain (loss) on sale	$ 7,000,000
Subsequent Event
Subsequent Events
Gain (loss) on sale		$ 16,000,000
Preferred equity investment
Subsequent Events
Preferred equity investment				$ 25,000,000	$ 25,000,000	$ 25,000,000
Carrying Value of Asset Net of Deferred Gain				0	0
Preferred equity investment | Subsequent Event
Subsequent Events
Preferred equity investment			$ 25,000,000
Proceeds received on sale of preferred equity investment and settlement of loan			16,000,000
Working capital advance provided to buyer
Subsequent Events
Carrying Value of Asset Net of Deferred Gain				$ 0	$ 0
Working capital advance provided to buyer | Subsequent Event
Subsequent Events
Working capital advance provided to buyer			$ 3,700,000