Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Jun. 22, 2016	Jun. 21, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares grant of future awards	200,600,000		200,600,000
Number of limited partnership units exchangeable into shares	16,400,000		16,400,000		13,900,000
Notional value with post-termination pay-out amount	$ 192,900,000		$ 192,900,000		$ 155,600,000
Aggregate estimated fair value of limited partnership units	$ 36,700,000		$ 36,700,000		$ 26,200,000
Number of unvested limited partnership units with post-termination pay-out	20,400,000		20,400,000		17,000,000
Number of outstanding limited partnership units, unvested	12,200,000		12,200,000		11,200,000
Income allocated to limited partnership units	$ 12,000,000	$ 10,400,000	$ 21,400,000	$ 15,500,000
Restricted stock unit, Conversion description			Each RSU is settled in one share of Class A common stock upon completion of the vesting period.
Shares, Forfeited			36,000	16,000
Number of shares released the restrictions			1,500,000	2,200,000
Cash received per share upon conversion			$ 6.10
Deferred cash compensation expense recognized	2,400,000	3,900,000	$ 6,208,000	$ 9,780,000
Liability for deferred cash compensation awards	12,700,000		12,700,000
Deferred cash compensation expense not yet recognized	9,500,000		$ 9,500,000
Deferred cash compensation expense, expected period of recognition			1 year 7 months 24 days
Exercise of stock options			0
Granted options			0
Compensation expense related to stock options	0	0	$ 0	$ 0
Equity Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise of stock options			0	250,000
Granted options			0	0
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	1,600,000	$ 1,200,000	$ 2,700,000	$ 2,800,000
Awards granted			618,317	700,000
Aggregate estimated grant date fair values			$ 6,200,000	$ 5,300,000
Value of shares withheld			2,200,000	$ 1,200,000
Aggregate estimated grant date fair value of outstanding RSUs	11,800,000		11,800,000		$ 10,600,000
Unrecognized compensation expense related to unvested RSUs	$ 11,500,000		$ 11,500,000
Restricted shares outstanding	1,441,105		1,441,105		1,547,402
Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares outstanding	10,500,000		10,500,000
Minimum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, restriction period			2 years
Minimum [Member] | Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares saleable period			5 years
Maximum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, restriction period			4 years
Maximum [Member] | Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares saleable period			10 years
Limited Partnership Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of limited partnership units granted exchangeability	3,600,000	3,500,000	8,900,000	6,700,000
Equity-based compensation expense	$ 38,200,000	$ 30,600,000	$ 92,000,000	$ 58,400,000
Aggregate estimated fair value of limited partnership units	22,500,000		22,500,000		$ 20,300,000
Compensation expense before income tax related to limited partnership units	$ 6,000,000	$ 4,600,000	$ 12,400,000	$ 6,700,000
Awards granted			21,880,083
Restricted shares outstanding	118,586,992		118,586,992		104,564,656
Limited Partnership Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, restriction period			3 years
Limited Partnership Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, restriction period			5 years
Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Forfeited	35,598	11,958	35,598	15,660	59,317
Equity Plan [Member] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to be delivered pursuant to awards granted						400,000,000	350,000,000