Annual report pursuant to Section 13 and 15(d)

Property and Equipment (Summary Of Property and Equipment) (Details)

v3.8.0.1
Property and Equipment (Summary Of Property and Equipment) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross $ 122,316 $ 114,692
Accumulated depreciation and amortization (47,560) (43,895)
Total $ 74,756 70,797
Maximum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 5 years  
Minimum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 3 years  
Office Equipment, Furniture And Fixtures [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross $ 57,334 50,524
Office Equipment, Furniture And Fixtures [Member] | Maximum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 14 years  
Office Equipment, Furniture And Fixtures [Member] | Minimum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 3 years  
Land, Buildings And Building Improvements [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross $ 56,639 56,211
Land, Buildings And Building Improvements [Member] | Maximum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 31 years  
Land, Buildings And Building Improvements [Member] | Minimum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 3 years  
Leasehold Improvements [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross $ 8,168 7,764
Leasehold Improvements [Member] | Maximum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 14 years  
Leasehold Improvements [Member] | Minimum [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 3 years  
Transportation And Equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross $ 175 $ 193
Property, Plant and Equipment, Useful Life 5 years