Annual report pursuant to Section 13 and 15(d)

Retirement Savings Plans (Narrative) (Details)

v3.3.1.900
Retirement Savings Plans (Narrative) (Details) - USD ($)
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Liability to participants under deferred compensation plan $ 6,887,000 $ 6,039,000  
Current liability to participants under deferred compensation plan 629,000 485,000  
401(k) Profit-Sharing Plan [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Company contributions to the plan 6,981,000 7,056,000 $ 5,200,000
Deferred Compensation Plan [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Company contributions to the plan 180,000 239,000 $ 483,000
Other Noncurrent Assets [Member] | Deferred Compensation Plan [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Fair value of mutual fund investments 6,887,000 6,039,000  
Short-term Investments [Member] | Deferred Compensation Plan [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Fair value of mutual fund investments $ 629,000 $ 485,000