XML 106 R11.htm IDEA: XBRL DOCUMENT

Accounts receivable and allowance for doubtful accounts	9 Months Ended
Accounts receivable and allowance for doubtful accounts	Sep. 30, 2019
Receivables [Abstract]
Accounts receivable and allowance for doubtful accounts	Accounts receivable and allowance for doubtful accounts Accounts receivable consists primarily of trade receivables from the sale of goods and services which are recorded at the invoiced amount net of allowance for doubtful accounts, and costs and estimated earnings in excess of billings on uncompleted contracts. The total balance of receivables past due 90 days or more was $56.0 million, $29.2 million and $30.0 million at September 30, 2019 and 2018, and December 31, 2018, respectively. The allowance for doubtful accounts is determined through a review of past due balances and other specific account data. Account balances are written off when management determines the amounts to be uncollectible. The Company's allowance for doubtful accounts at September 30, 2019 and 2018, and December 31, 2018, was $8.7 million, $7.3 million and $8.9 million, respectively.