Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments - Narratives (Details)

v3.8.0.1
Financial Instruments - Narratives (Details)
€ in Thousands, MMBTU in Millions
1 Months Ended 3 Months Ended
Jul. 31, 2016
USD ($)
Mar. 31, 2018
USD ($)
MMBTU
Mar. 31, 2018
EUR (€)
Derivative      
Derivative, notional quantity (in MMBTU) | MMBTU   3.4  
Amount of derivative loss expected to be transferred from OCI   $ 590,000  
Interest rate caps      
Derivative      
Premium paid to acquire derivative instrument $ 1,551,000    
Derivative, cap interest rate   2.00% 2.00%
Derivative, notional amount $ 1,000,000    
Interest rate caps | Minimum      
Derivative      
Derivative, cap interest rate 1.50%    
Interest rate caps | Maximum      
Derivative      
Derivative, cap interest rate 3.00%    
Currency swap      
Derivative      
Derivative instrument   $ 345,041,000 € 280,000