v3.8.0.1
ACQUISITIONS Table 1 - Navigator Acquisition Preliminary Purchase Price Allocation (Details) - USD ($)
$ in Thousands
May 04, 2017
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Business Acquisition [Line Items]        
Goodwill   $ 1,097,475 $ 696,637 $ 696,637
Navigator Acquisition [Member]        
Business Acquisition [Line Items]        
Accounts receivable $ 4,747      
Other current assets 2,359      
Property, plant and equipment, net 376,690      
Intangible assets 700,000      
Goodwill 400,838      
Other long-term assets, net 2,199      
Current liabilities (25,114)      
Preliminary purchase price allocation, net of cash acquired $ 1,461,719      
Intangible assets, weighted average useful life (years) 20 years