Fair Value Measurements (Details) $ in Thousands	Dec. 31, 2015 USD ($) item	Dec. 31, 2014 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded derivative	$ (193,077)
Number of interest rate derivatives | item	0
Netting Cash and Collateral [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets		$ (90)
Derivative liabilities		90
Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets	$ 31,018	22,829
Embedded derivative	(193,077)
Total net assets	(162,059)	22,829
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets	31,018	22,919
Derivative liabilities		(90)
Total net assets	31,018	$ 22,829
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded derivative	(193,077)
Total net assets	$ (193,077)