Annual report pursuant to Section 13 and 15(d)

Summary of Potential Number of Shares Vesting under Restricted Stock Unit Awards (Detail)

v3.3.1.900
Summary of Potential Number of Shares Vesting under Restricted Stock Unit Awards (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Schedule of Restricted Stock Unit [Line Items]      
Number of units at IRR level of at least 8.5% 47,640 65,832 38,366
Number of units at IRR level of at least 10.5% 95,282 131,683 76,741
Number of units at IRR level of at least 12.5% 142,917 197,515 115,107
Fair value of units at IRR level of at least 8.5% [1] $ 2,057 $ 1,879 $ 1,129
Fair value of units at IRR level of at least 10.5% [1] 4,115 3,758 2,259
Fair value of units at IRR level of at least 12.5% [1] $ 6,173 $ 5,637 $ 3,389
At IRR of at least 7.5% 47,640 65,832 38,366
At IRR of at least 9.5% 95,282 131,683 76,741
At IRR of at least 11.5% 142,917 197,515 115,107
IRR of at least 7.5% [1] $ 2,057 $ 1,879 $ 1,129
IRR of at least 9.5% [1] 4,115 3,758 2,259
IRR of at least 11.5% [1] $ 6,173 $ 5,637 $ 3,389
[1] The weighted average grant date fair values for units issued during the years ended December 31, 2013, 2014, and 2015 were $29.44, $28.54 and $43.19, respectively.