Derivatives and Hedging Activities Effect of Derivative Instruments on Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ 121	[1]	$ 663	[1]	$ (237)	[2]	$ (1,928)	[2]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(293)		(405)		(953)		(1,319)
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net	(1)		(19)		(3)		26
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	(293)		(405)		(953)		(1,319)
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	$ 121	[1]	$ 663	[1]	$ (237)	[2]	$ (1,928)	[2]

[1] There was an additional $(1) thousand loss related to the ineffective portion for the three months ended as of September 30, 2017 and a $(19) thousand loss related to the ineffective portion for the three months ended as of September 30, 2016.

[2] There was an additional $(3) thousand loss related to the ineffective portion for the nine months ended as of September 30, 2017 and a $26 thousand gain related to the ineffective portion for the nine months ended as of September 30, 2016.