Earnings Per Unit Calculation - Schedule of Partnership's Basic Earnings (Loss) Per Common and Subordinated Unit (Detail) - USD ($)
$ / shares in Units, $ in Thousands
2 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2013
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]                        
Net income   $ 28,379 $ 8,580 $ (2,550) $ 43,939 $ 65,588 $ (5,302) $ (10,604) $ 73,132 $ 78,348 $ 122,814 $ (29,838)
Predecessor income through October 29, 2013                   0 0 (2,734)
Income attributable to Kildair (Note 2)                   0 (4,080) 2,338
Distributions declared                   42,090 35,490 5,692
Assumed net income from operations after distributions                   36,258 83,244 (35,926)
Assumed net income to be allocated $ (32,572) $ 28,212 $ 8,475 $ (2,599) $ 43,939 $ 63,611 $ (10,718) $ (9,494) $ 75,335 $ 78,027 $ 118,734 $ (30,234)
Income per unit - basic   $ 1.34 $ 0.40 $ (0.12) $ 2.10 $ 3.13 $ (0.53) $ (0.47) $ 3.74 $ 3.71 $ 5.88 $ (1.50)
Income per unit - diluted   $ 1.32 $ 0.39 $ (0.12) $ 2.06 $ 3.07 $ (0.53) $ (0.47) $ 3.74 $ 3.65 $ 5.84 $ (1.50)
Common Unitholders - Affiliated [Member]                        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]                        
Net income                   $ 40,689    
Distributions declared                   21,826 $ 17,964 $ 2,846
Assumed net income from operations after distributions                   $ 18,863 41,579 (17,963)
Assumed net income to be allocated                     $ 59,543 $ (15,117)
Income per unit - basic                   $ 3.71 $ 5.88 $ (1.50)
Income per unit - diluted                   $ 3.65 $ 5.84 $ (1.50)
Subordinated Unitholders - Affiliated [Member]                        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]                        
Net income                   $ 37,338    
Distributions declared                   19,943 $ 17,526 $ 2,846
Assumed net income from operations after distributions                   $ 17,395 41,665 (17,963)
Assumed net income to be allocated                     $ 59,191 $ (15,117)
Income per unit - basic                   $ 3.71 $ 5.88 $ (1.50)
Income per unit - diluted                   $ 3.71 $ 5.88 $ (1.50)
Incentive Distribution Rights [Member]                        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]                        
Net income                   $ 321    
Distributions declared                   321    
Assumed net income from operations after distributions                   $ 0