Schedule of Outstanding Interest Rate Swaptions (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Weighted Average Months to Expiration	11 months	12 months
Options
Derivative [Line Items]
Original Cost	$ 6,813,000	$ 10,813,000
Fair Value	$ 6,000	$ 727,000
Weighted Average Months to Expiration	4 months	6 months
Underlying Swaps
Derivative [Line Items]
Notional Amount	$ 2,000,000,000	$ 3,065,000,000
Weighted Average Fixed Pay Rate	3.35%	3.23%
Weighted Average Term (Years)	6 years	6 years