Derivative Financial Instruments Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017 USD ($) contracts	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2016 USD ($) contracts	Mar. 31, 2016 USD ($)
Net unrealized loss on hedging instruments	$ 213,618		$ 229,327
Secured Debt [Member]
Total debt	304,438		305,292
Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]
Net unrealized loss on hedging instruments	$ 14,380	$ 14,380	$ 14,380		$ 14,380
Number of Counterparties [Member]
Derivative Counterparties	3		3
London Interbank Offered Rate (LIBOR) [Member] | Secured Debt [Member]
Total debt	$ 245,300
Interest Rate Swap [Member]
Number of Interest Rate Derivatives Held | contracts	1			6
Derivative, Notional Amount	$ 214,000			$ 200,000
Pay fixed interest rate in interest rate swap	1.42%			1.00%
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ (500)
Interest Rate Cap [Member]
Number of Interest Rate Derivatives Held | contracts	3
Derivative, Notional Amount	$ 100,000
Derivative, Cap Interest Rate	2.00%
Derivative Purchase Price		$ 1,700
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ (200)
Forward Contracts [Member]
Description of Derivative Activity Volume	49
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Minimum [Member]
Derivative, Notional Amount	$ 167
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Maximum [Member]
Derivative, Notional Amount	$ 45,300