Business Combinations Business Combinations (Tables)
 12 Months Ended
Dec. 31, 2016
Business Combinations [Abstract]  
Schedule of Fair Value of Assets and Acquired and Liabilities Assumed
The following table summarizes the fair values of the assets acquired and liabilities assumed: 
Derivative assets
 
 
 
 
$
22,678

Other current assets and prepaids
 
 
 
 
2,168

Intangibles and other
 
 
 
 
6,539

Natural gas transportation assets
 
 
 
 
8,040

Total identifiable assets acquired
 
 
 
 
39,425

Accrued liabilities
 
 
 
 
(219
)
Derivative liabilities
 
 
 
 
(15,007
)
Natural gas transportation liabilities
 
 
 
 
(2,396
)
Total liabilities assumed
 
 
 
 
(17,622
)
Net identifiable assets acquired
 
 
 
 
21,803

Goodwill
 
 
 
 
7,262

Net assets acquired
 
 
 
 
$
29,065