XML 19 R61.htm IDEA: XBRL DOCUMENT v3.19.3
Other commitments and contingencies (Details) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Environmental matters [Line Items]    
Accruals for environmental matters $ 2,272 $ 2,755
Self-insurance    
Self-insurance liabilities 7,596 6,627
Environmental insurance policy through 2032 [Member]    
Environmental matters [Line Items]    
Environmental insurance coverage 10,000  
Environmental insurance policy through 2022 [Member]    
Environmental matters [Line Items]    
Environmental insurance coverage 15,000  
Environmental insurance policies in effect [Member]    
Environmental matters [Line Items]    
Accruals for environmental matters $ 0 $ 0