Stock-Based Compensation (Tables)
 9 Months Ended
Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Schedule of Compensation Expense
Upon adoption of ASU 2016-09 in October 2016, the Company elected to account for forfeitures of awards granted under these plans as they occur in determining compensation expense.
(in thousands)
For the Three Months Ended September 30, 2017
 
For the Nine Months Ended September 30, 2017
Restricted stock awards
$
1,490

 
$
3,364

Stock option awards
2,104

 
5,825

Performance stock units
231

 
231

Total stock-based compensation expense
$
3,825

 
$
9,420
Nonvested Restricted Stock Shares Activity
The following table provides information about restricted stock awards outstanding during the nine months ended September 30, 2017:
 
Awards
 
Weighted Average Grant-Date Fair Value
Outstanding as of December 31, 2016
256,597

 
$
20.03

Vested
—

 
$
—

Granted
841,443

 
$
17.21

Forfeited
(8,788
)
 
$
18.81

Outstanding as of September 30, 2017
1,089,252

 
$
17.86
Summary of Option Valuation Inputs
The following table summarizes the assumptions and related information used to determine the grant-date fair value of stock options awarded during the nine months ended September 30, 2017:
 
Nine Months Ended September 30, 2017
Weighted average grant-date fair value per share
$
7.15

Expected term (in years)
6

Expected stock volatility
38.1
%
Dividend yield
—
%
Risk-free interest rate
2.0
%
Summary of Stock Option Activity
The following table provides information about stock option awards outstanding during the nine months ended September 30, 2017:
 
Options
 
Weighted Average Exercise Price
 
Weighted Average Remaining Term
(in years)
 
Aggregate Intrinsic Value
(in thousands)
Outstanding as of December 31, 2016
2,735,500

 
$
14.67

 
 
 
 
Exercised
—

 
$
—

 
 
 
 
Granted
1,550,000

 
$
17.96

 
 
 
 
Forfeited
(268,000
)
 
$
14.53

 
 
 
 
Outstanding as of September 30, 2017
4,017,500

 
$
15.95

 
9.2

 
$
8,450

Exercisable as of September 30, 2017
—

 
$
—

 
—

 
$
—
Summary of Fair Value Inputs For Performance Stock Units
The following table summarizes the key assumptions and related information used to determine the grant-date fair value of performance stock units awarded during the nine months ended September 30, 2017:
 
 
Nine Months Ended September 30, 2017
Number of simulations
 
1,000,000

Expected stock volatility
 
41.6
%
Dividend yield
 
—
%
Risk-free interest rate
 
1.5
%
Performance Stock Units Outstanding Activity
The following table provides information about performance stock units outstanding during the nine months ended September 30, 2017:
 
Awards
 
Weighted Average Grant-Date Fair Value
Outstanding as of December 31, 2016
—

 
$
—

Vested
—

 
$
—

Granted
193,391

 
$
21.53

Forfeited
—

 
$
—

Outstanding as of September 30, 2017
193,391

 
$
21.53