XML 68 R57.htm IDEA: XBRL DOCUMENT v3.19.1
Equity Incentive Plans and Stock-Based Compensation (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Employee Stock [Member]    
Stock-Based Compensation    
Stock-based compensation $ 0.5 $ 0.5
Shares available for grant    
Shares available, at the end of the period 2,294,878  
Stock-Based Incentive Compensation Plans    
Shares available for grant    
Shares available, at the beginning of the year 10,074,046  
Stock options granted (in shares) 0  
Stock options forfeited (in shares) 33,967  
Nonvested equity stock and stock units granted (in shares) [1],[2] (5,907,629)  
Nonvested equity stock and stock units forfeited (in shares) [2] 315,349  
Shares available, at the end of the period 4,515,733  
Conversion factor used to calculate the decrease in the number of shares available for grant resulting from the grant of restricted stock awards 1.5  
Conversion factor used to calculate the increase in the number of shares available for grant resulting from the forfeiture of restricted stock awards 1.5  
Restricted Stock and Stock Units [Member]    
Stock-Based Compensation    
Stock-based compensation $ 6.4 $ 6.5
Potential Additional Performance Stock Units [Domain]    
Shares available for grant    
Nonvested equity stock and stock units granted (in shares) [1],[2] 853,313  
[1] Amount includes approximately 0.9 million shares that have been reserved for potential future issuance related to certain performance unit awards granted in the first quarter of 2019 and discussed under the section titled "Nonvested Equity Stock and Stock Units" below.
[2] For purposes of determining the number of shares available for grant under the 2015 Equity Incentive Plan (the “2015 Plan”) against the maximum number of shares authorized, each share of restricted stock granted reduces the number of shares available for grant by 1.5 shares and each share of restricted stock forfeited increases shares available for grant by 1.5 shares.