Incentive Award Plan and Employee Benefit Plan - Additional Information (Details) - USD ($)
$ in Thousands |
1 Months Ended |
12 Months Ended |
Aug. 31, 2013 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Shares of common stock available for issuance |
|
4,100,000
|
|
|
| Value of shares surrendered for payment of federal and state withholding taxes |
|
$ 3,542
|
$ 753
|
$ 4,272
|
| Unamortized stock-based compensation expense |
|
$ 17,700
|
|
|
| Requisition service period |
|
3 months
|
|
|
| General and Administrative Expense |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Stock-based compensation expense |
|
$ 16,600
|
$ 9,600
|
$ 13,300
|
| Maximum |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Percentage of employer matching contribution (up to) |
|
4.00%
|
|
|
| Restricted Stock |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Shares surrendered for payment of federal and state withholding taxes |
|
400,000
|
100,000
|
400,000
|
| Value of shares surrendered for payment of federal and state withholding taxes |
|
$ 3,500
|
$ 800
|
$ 4,300
|
| Grants in period (in shares) |
|
1,103,563
|
948,793
|
495,688
|
| Deferred compensation expense |
|
$ 9,900
|
|
|
| Requisite service period of awards |
|
3 years
|
|
|
| Weighted average recognition period |
|
1 year 10 months 24 days
|
|
|
| Unamortized stock-based compensation expense |
|
$ 10,000
|
|
|
| Restricted Stock | Directors Officers and Employees |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Grants in period (in shares) |
|
1,100,000
|
|
|
| Performance Shares |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Grants in period (in shares) |
|
858,226
|
400,800
|
279,199
|
| Vesting Period |
3 years
|
|
|
|
| Weighted average recognition period |
|
2 years 2 months 15 days
|
|
|
| Accrued dividend rights |
|
$ 800
|
$ 500
|
|
| Aggregate shares that would have released under annual performance award |
|
1,000,000
|
|
|
| Unamortized stock-based compensation expense |
|
$ 7,700
|
|
|
| Performance Shares | Minimum |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Percent multiplier for shares granted |
0.00%
|
|
|
|
| Performance Shares | Maximum |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Percent multiplier for shares granted |
250.00%
|
|
|
|