Partnership Distributions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
Jan. 27, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Distribution Made to Limited Partner [Line Items] | ||||
| Cash distribution, declared per share (in dollars per share) | $ 2.22 | $ 1.9800 | $ 1.7400 | |
| Incentive Distribution Rights | Dividend Declared on January 27, 2017 | ||||
| Distribution Made to Limited Partner [Line Items] | ||||
| Cash distribution, declared value | $ 0.3 | |||
| Subsequent Event | Dividend Declared on January 27, 2017 | ||||
| Distribution Made to Limited Partner [Line Items] | ||||
| Cash distribution, declared per share (in dollars per share) | $ 0.5775 | |||
| Cash distribution, declared value | $ 13.0 | |||
| Subsequent Event | Incentive Distribution Rights | Dividend Declared on January 27, 2017 | ||||
| Distribution Made to Limited Partner [Line Items] | ||||
| Cash distribution, declared value | $ 0.6 | |||