XML 64 R53.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-based Compensation (Narrative) (Details) - shares
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Market-based awards    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted, Shares 29,715 51,221
Average period based on relative TSR 3 years  
Market-based awards | Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance metric achieved 100.00%  
Performance And Market-Based Restricted Stock Units | Minimum [Member] | Senior management    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance metric, potential range 0.00%  
Performance And Market-Based Restricted Stock Units | Maximum [Member] | Senior management    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance metric, potential range 150.00%  
Market Based Awards That Achieved Payout In Excess Of 1[Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted, Shares 3,115 5,681
Performance-based restricted stock units    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted, Shares 0 0
Performance metric achieved 100.00%  
Performance-based restricted stock units | Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance metric, potential range 0.00%  
Performance-based restricted stock units | Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance metric, potential range 200.00%  
2014 Stock Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of shares available for grant 4,146,549  
ESPP Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of shares available for grant 2,387,199  
SIP Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of shares available for grant 683,058