Derivative Instruments Derivative gain loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Interest Rate Swap No. 2 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
5 yr Interest Rate Swap	$ 388	$ 100
Interest Rate Derivative Liabilities, at Fair Value	353	201
Interest Rate Swap No. 1 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
5 yr Interest Rate Swap	583	145
Interest Rate Derivative Liabilities, at Fair Value	1,229	881
Interest Rate Swap [Domain]
Derivative Instruments, Gain (Loss) [Line Items]
5 yr Interest Rate Swap	971	245
Interest Rate Derivative Liabilities, at Fair Value	$ 1,582	$ 1,082