Income Taxes - Additional information (Detail) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) shares	Jun. 30, 2016 USD ($) shares	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Sep. 30, 2016 USD ($) Agreement	Dec. 31, 2015 USD ($)
Tax Credit Carryforward [Line Items]
Effective income tax rate					39.50%
Effective income tax rate reconciliation noncontrolling interest					2.10%
Net deferred tax assets	$ 255,729		$ 255,729		$ 255,729	$ 117,358
Net deferred tax liabilities	1,275		1,275		1,275	$ 0
Total liability related to uncertain tax positions	$ 300		$ 300		$ 300
Number of tax receivable agreements | Agreement					2
Applicable percentage of cash savings	85.00%	85.00%	85.00%	85.00%	85.00%
Percentage of remaining tax savings					15.00%
Income tax rate maximum tax liability					3.50%
Tax benefit obligation	$ 274,072		$ 274,072		$ 274,072
Continuing LLC Owners [Member]
Tax Credit Carryforward [Line Items]
Decrease in deferred tax assets			(5,378)	$ (7,638)
Deferred tax asset	71,174	$ 89,876	71,174	89,876	71,174
Deferred tax liability	$ 61,735	$ 78,152	61,735	$ 78,152	61,735
Class A Common Stock [Member] | Continuing LLC Owners [Member]
Tax Credit Carryforward [Line Items]
Number of shares exchanged | shares	5,406,019	7,891,160
Canada [Member]
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	$ 1,911		$ 1,911		$ 1,911
Operating loss carryforwards, expiration date					2034