Derivatives and Hedging Activities Effect of Derivative Instruments on Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016		Jun. 30, 2017		Jun. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ (425)	[1]	$ (643)	[1]	$ (358)	[2]	$ (2,591)	[2]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(357)		(453)		(660)		(914)
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net	2		3		(2)		45
Interest Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(357)		(453)		(660)		(914)
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ (425)	[1]	$ (643)	[1]	$ (358)	[2]	$ (2,591)	[2]

[1] There was an additional $2 thousand gain related to the ineffective portion for the three months ended as of June 30, 2017 and $3 thousand gain related to the ineffective portion for the three months ended as of June 30, 2016.

[2] There was an additional $2 thousand loss related to the ineffective portion for the six months ended as of June 30, 2017 and $45 thousand gain related to the ineffective portion for the six months ended as of June 30, 2016.