Derivatives (Interest Rate Swap) (Details) - Interest Rate Swap - Cash Flow Hedging - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest Expense
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			$ (1,000)
Senior Loans
Derivative [Line Items]
Derivative, Notional Amount	$ 220,000		$ 220,000
Derivative, Fixed Interest Rate	4.85%		4.85%
Designated as Hedging Instrument
Derivative [Line Items]
Effective portion of derivative gain (loss) recognized in other comprehensive income (loss)	$ (619)	$ (1,603)	$ (415)	$ (4,822)
Effective portion of derivative gain (loss) reclassified from accumulated other comprehensive loss into income (loss)	(472)	(620)	(1,057)	(1,011)
Designated as Hedging Instrument | Interest Expense
Derivative [Line Items]
Effective portion of derivative gain (loss) reclassified from accumulated other comprehensive loss into income (loss)	$ (472)	$ (620)	$ (1,057)	$ (1,011)