Derivatives and Hedging Activities Effect of Derivative Instruments on Statement of Operations (Details) - USD ($)		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net		$ 6,000	$ 0
Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1]	(799,000)	(2,642,000)
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		(1,672,000)	(4,052,000)
Interest Rate Contract [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1]	(799,000)	(2,642,000)
Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		$ (1,672,000)	$ (4,052,000)

[1] There was an additional $6 thousand related to the ineffective portion for the year ended December 31, 2016 and no ineffective portion for the year ended December 31, 2015.