Trade Accounts Receivable	3 Months Ended
Trade Accounts Receivable	Mar. 31, 2018
Trade Accounts Receivable
Trade Accounts Receivable	(2) Trade Accounts Receivable Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for doubtful accounts, which was $0.3 million and $0.4 million at March 31, 2018 and December 31, 2017, respectively, is our best estimate of the amount of probable credit losses included in our existing accounts receivable. We determine the allowance based upon historical write-off experience and specific customer circumstances. The determination of the allowance for doubtful accounts requires us to make estimates and judgments regarding our customers’ ability to pay amounts due. On an ongoing basis, we conduct an evaluation of the financial strength of our customers based on payment history, the overall business climate in which our customers operate and specific identification of customer bad debt and make adjustments to the allowance as necessary. Our evaluation of our customers’ financial strength is based on the aging of their respective receivables balance, customer correspondence, financial information and third-party credit ratings. Our evaluation of the business climate in which our customers operate is based on a review of various publicly-available materials regarding our customers’ industries, including the solvency of various companies in the industry. During the three months ended March 31, 2018, we reduced our allowance for doubtful accounts by $0.1 million due to write-offs of bad debt. During the three months ended March 31, 2017, we reduced our allowance for doubtful accounts by $0.1 million due to collections on accounts that had previously been reserved.

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.