Annual report pursuant to Section 13 and 15(d)

Income Taxes - Summary of Reconciles Provision for Income Taxes (Detail)

v3.8.0.1
Income Taxes - Summary of Reconciles Provision for Income Taxes (Detail)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Reconciliation of federal statutory tax rate to effective rate      
Statutory U.S. federal income tax rate 35.00% 35.00% 35.00%
Income passed through to Partners (11.38%) (14.17%) (12.43%)
State and local income taxes 8.14% 9.78% 18.50%
Permanent items (6.70%) 0.33% (2.18%)
Discrete expenses due to Corporate Tax Reform 27.69% 0.00% 0.00%
Other (0.46%) 1.01% (0.29%)
Effective income tax rate 52.29% 31.95% 38.60%