Annual report pursuant to Section 13 and 15(d)

Summary of Common Units Received Under Adjustment Agreement (Detail)

v3.6.0.2
Summary of Common Units Received Under Adjustment Agreement (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]      
Fair Value of Common Units Received $ 11,111 $ 15,421 $ 8,216
Annual Common Unit Adjustment      
Schedule of Equity Method Investments [Line Items]      
Fair Value of Common Units Received $ 11,111 $ 15,421 $ 8,216
Number of Common Units Received 753,598 1,074,910 557,631
Date Common Units Received Mar. 31, 2016 Mar. 31, 2015 Mar. 27, 2014