Equity-Based Compensation - Additional Information (Detail) - USD ($) | Feb. 19, 2015 | Jun. 11, 2014 | Apr. 14, 2014 | Mar. 31, 2016 | Mar. 31, 2015 | Dec. 31, 2015 | Dec. 31, 2014 | Nov. 25, 2014 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Expense accrued or recognized for Units granted | | | | $ 31,663,000 | | $ 30,918,000 | | |
Total compensation expense | | | | $ 2,490,000 | $ 8,969,000 | | | |
Common Stock, shares issued | | | | 131,578,163 | | 130,974,073 | | |
Performance Unit Grant II [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Grant-date fair value per share | $ 25.35 | | | | | | | |
Promote Plan [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Expense accrued or recognized for Units granted | | | $ 0 | | | | | |
Issuance of vested and unvested restricted shares | | | 3,100,000 | | | | | |
Initial public offering price | | | $ 17 | | | | | |
Total compensation expense | | | | | 500,000 | | | |
Promote Plan [Member] | Restricted Stock [Member] | Tranche Two [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares vested | | | 40.00% | | | | | |
Promote Plan [Member] | Restricted Stock [Member] | Blackstone [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares outstanding | | | | | | | | 50.00% |
Promote Plan [Member] | Restricted Stock [Member] | Blackstone [Member] | Tranche Three [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares vested | | | 20.00% | | | | | |
Promote Plan [Member] | Common Stock [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares outstanding | | | 50.00% | | | | | |
Promote Plan [Member] | Common Stock [Member] | Tranche One [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares vested | | | 40.00% | | | | | |
2014 Omnibus Incentive Plan [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Issuance of vested and unvested restricted shares | | | 350,000 | | | | | |
Initial public offering price | | | $ 16.65 | | | | | |
Total compensation expense | | | | $ 2,500,000 | $ 3,900,000 | | | |
Grant-date fair value | | $ 19.80 | | | | | | |
Forfeited shares for stock based compensation | | | | 57,729 | | | | |
Unrecognized compensation expense | | | | $ 19,300,000 | | | | |
Share reserved for purchase | | | | 11,200,000 | | | | |
2014 Omnibus Incentive Plan [Member] | Restricted Stock [Member] | Tranche Two [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares vested | | | 40.00% | | | | | |
2014 Omnibus Incentive Plan [Member] | Restricted Stock [Member] | Blackstone [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares outstanding | | | | | | | | 50.00% |
2014 Omnibus Incentive Plan [Member] | Restricted Stock [Member] | Blackstone [Member] | Tranche Three [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares vested | | | 10.00% | | | | | |
2014 Omnibus Incentive Plan [Member] | Omnibus Incentive Plan Grant II [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Common Stock, shares issued | | 1,010,000 | | | | | | |
Grant price | | $ 18.70 | | | | | | |
Performance unit grant, remaining life | | | | 8 months 12 days | | | | |
2014 Omnibus Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Performance unit grant, remaining life | | | | 1 year 1 month 6 days | | | | |
Shares granted during the period | | | | | | 44,197 | 44,197 | |
Shares granted vesting description | | | | The Director Unit Grants vest in three equal installments on the first, second and third anniversaries of the grant dates | | | | |
Grant-date fair value | | | | | | $ 21.32 | $ 21.32 | |
2014 Omnibus Incentive Plan [Member] | Performance-based RSUs [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Common Stock, shares issued | | 500,000 | | | | | | |
Performance unit grant, remaining life | | | | 9 months 18 days | | | | |
Restricted stock units issued | | 109 | | | | | | |
Description of value of units granted under the plan | | | | The calculation of the value of the units granted under the 2014 Performance Unit Grant is weighted as follows: 70% based on our total shareholder return (“TSR”) relative to the total shareholder returns of a defined set of peer companies (“Relative Shareholder Return”); and 30% based on our absolute TSR compound annual growth rate (“TSR CAGR”). | | | | |
2014 Omnibus Incentive Plan [Member] | Performance-based RSUs [Member] | Minimum [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Payout range | | 33.00% | | | | | | |
2014 Omnibus Incentive Plan [Member] | Performance-based RSUs [Member] | Maximum [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Payout range | | 167.00% | | | | | | |
2014 Omnibus Incentive Plan [Member] | 2015 Grant I [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Common Stock, shares issued | | | | | | 200,000 | | |
Performance unit grant, remaining life | | | | 1 year 2 months 12 days | | | | |
Grant date weighted average price of awards | | | | | | $ 21.81 | | |
2014 Omnibus Incentive Plan [Member] | 2016 Grant I [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Common Stock, shares issued | | | | 400,000 | | | | |
Performance unit grant, remaining life | | | | 1 year 9 months 18 days | | | | |
Grant date weighted average price of awards | | | | $ 11.81 | | | | |
2014 Omnibus Incentive Plan [Member] | 2016 Grant II [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Common Stock, shares issued | | | | 200,000 | | | | |
Performance unit grant, remaining life | | | | 2 years 10 months 24 days | | | | |
Grant date weighted average price of awards | | | | $ 11.52 | | | | |
Performance awards performance period | | | | 3 years | | | | |
2014 Omnibus Incentive Plan [Member] | Common Stock [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares outstanding | | | 50.00% | | | | | |
2014 Omnibus Incentive Plan [Member] | Common Stock [Member] | Tranche One [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Percentage of common shares vested | | | 50.00% | | | | | |
Common stock vested, date | | | | Apr. 14, 2015 | | | | |
2014 Omnibus Incentive Plan Performance UG II [Member] | Performance-based RSUs [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Common Stock, shares issued | 300,000 | | | | | | | |
Performance unit grant, remaining life | | | | 1 year 9 months 18 days | | | | |
Description of value of units granted under the plan | | | | The calculation of the value of the units granted under the 2015 Performance Unit Grant is based solely on our TSR relative to the Relative Shareholder Return. | | | | |
2014 Omnibus Incentive Plan Performance UG II [Member] | Performance-based RSUs [Member] | Minimum [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Payout range | 33.00% | | | | | | | |
2014 Omnibus Incentive Plan Performance UG II [Member] | Performance-based RSUs [Member] | Maximum [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | |
Payout range | 200.00% | | | | | | | |