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Stock-Based Compensation (Narrative) (Details)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2020
USD ($)
item
shares
Mar. 31, 2019
USD ($)
Dec. 31, 2019
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense | $ $ 13,065 $ 12,828  
Restricted Stock Units (RSUs) [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares authorized 7,758,000    
Requisite service period 3 years 6 months    
Awards granted 303,385    
Performance Stock Units (PSUs) [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Requisite service period 3 years 6 months    
Awards granted 249,564   155,872
Increase (decrease) in units (40,509)    
Performance Stock Units, Market Condition [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance issuance as percent or original grant, in the event of negative shareholder return 100.00%    
Number of tranches | item 5    
Awards granted    
Increase (decrease) in units 7,672    
Performance Stock Units, Market Condition [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance issuance as percent or original grant 50.00%    
Performance Stock Units, Market Condition [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Performance issuance as percent or original grant 175.00%