Stock-Based Compensation - Additional Information (Details)
3 Months Ended
Mar. 31, 2015
Jun. 07, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Common shares reserved for issuance under stock-based employee compensation program 4,943,170  
Common stock available for issuance under Equity Plan 552,234 1,422,130
Stock Options [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period, in years 4 years  
Restricted Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period, in years 4 years  
Performance Stock Awards [Member] | Granted Prior to 2015 [Member] | Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period, in years 2 years  
Performance Stock Awards [Member] | Granted Prior to 2015 [Member] | Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period, in years 3 years  
Performance Stock Awards [Member] | Granted in 2015 [Member] | Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period, in years 3 years  
Performance Stock Awards [Member] | Granted in 2015 [Member] | Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period, in years 4 years