Derivative Financial Instruments - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Loss on debt extinguishment, modifications and termination of derivative instruments	$ 47,559	$ 986	$ 1,437
Cross-currency swap asset	2,283	0
Cash Flow Hedging | Interest Rate Swap
Derivative [Line Items]
Interest rate swap liability		2,500
Cash Flow Hedging | Cross Currency Swap Agreements
Derivative [Line Items]
Cross-currency swap asset	2,300
Cash flow hedge derivatives | Loss on debt extinguishment, modifications and termination of derivative instruments
Derivative [Line Items]
Net amount reclassified from AOCI to net income/loss		$ 0	$ 0
Cash flow hedge derivatives | Loss on debt extinguishment, modifications and termination of derivative instruments | Reclassification out of Accumulated Other Comprehensive Income | ANZ Loans | Term Loans | Interest Rate Swap
Derivative [Line Items]
Net amount reclassified from AOCI to net income/loss	$ 1,825