Partnership Distributions - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Jan. 27, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Distribution Made to Limited Partner [Line Items]        
Cash distribution, declared per share   $ 1.9800 $ 1.7400 $ 0.2825
Subsequent Event [Member] | Dividend Declared on January 27, 2016 [Member]        
Distribution Made to Limited Partner [Line Items]        
Cash distribution, declared value $ 11.1      
Cash distribution, declared per share $ 0.5175      
Subsequent Event [Member] | Incentive Distribution Rights [Member] | Dividend Declared on January 27, 2016 [Member]        
Distribution Made to Limited Partner [Line Items]        
Cash distribution, declared value $ 0.2