Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments - Effect on Other Comprehensive Income (Details)

v3.19.1
Financial Instruments - Effect on Other Comprehensive Income (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Amount of gain (loss) recognized in OCI on derivatives    
Amount of gain (loss) recognized in OCI on derivatives $ (2,002) $ 2,905
Amount of gain (loss) reclassified from AOCI into income    
Amount of gain (loss) reclassified from AOCI into income 68 (7)
Interest rate caps    
Amount of gain (loss) recognized in OCI on derivatives    
Amount of gain (loss) recognized in OCI on derivatives (2,373) 2,852
Interest rate caps | Interest expense    
Amount of gain (loss) reclassified from AOCI into income    
Amount of gain (loss) reclassified from AOCI into income (123) (35)
Natural gas swaps    
Amount of gain (loss) recognized in OCI on derivatives    
Amount of gain (loss) recognized in OCI on derivatives 371 53
Natural gas swaps | Cost of goods sold    
Amount of gain (loss) reclassified from AOCI into income    
Amount of gain (loss) reclassified from AOCI into income $ 191 $ 28