Derivatives and Hedging Activities Effect of Derivative Instruments on Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2016		Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ 663	[1]	$ (1,896)	[1]	$ (1,928)	[2]	$ (3,629)	[2]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(405)		(1,026)		(1,319)		(3,066)
Derivative Instruments, Gain Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing	(19)		0		26		0
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	(405)		(1,026)		(1,319)		(3,066)
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	$ 663	[1]	$ (1,896)	[1]	$ (1,928)	[2]	$ (3,629)	[2]

[1] There was an additional $(19) thousand related to the ineffective portion for the three months ended as of September 30, 2016 and no ineffective portion for the three months ended as of September 30, 2015.

[2] There was an additional $26 thousand related to the ineffective portion for the nine months ended as of September 30, 2016 and no ineffective portion for the nine months ended as of September 30, 2015.