XML 44 R34.htm IDEA: XBRL DOCUMENT v3.7.0.1
Cash Equivalents And Restricted Securities (Summary Of Cash Equivalents And Restricted Securities) (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Mar. 31, 2016
Dec. 31, 2015
Cash and Cash Equivalents [Line Items]        
Cash Equivalents, Cost Basis $ 58,882 $ 56,642 $ 44,827 $ 37,588
Restricted Securities, Cost Basis 713 699    
Money Market Funds [Member]        
Cash and Cash Equivalents [Line Items]        
Cash Equivalents, Cost Basis 3,469 3,466    
Restricted Securities, Cost Basis 713 699    
Unrealized Holding Gains    
Cash Equivalents, Estimated Market Value 3,469 3,466    
Restricted Securities, Estimated Market Value $ 713 $ 699