XML 39 R26.htm IDEA: XBRL DOCUMENT v3.3.1.900
Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]  
Changes in the allowance for doubtful accounts receivable
The following table summarizes the changes in the allowance for doubtful accounts receivable for the indicated periods:
 
 
Balance at beginning of year
 
Additions charged to earnings
 
Uncollectible receivables written off, net of recoveries
 
Balance at
end of year
 
 
 
 
 
 
 
 
 
December 31, 2015
 
1,950

 
869

 
(877
)
 
1,942

December 31, 2014
 
2,893

 
769

 
(1,712
)
 
1,950

December 31, 2013
 
2,563

 
1,442

 
(1,112
)
 
2,893