Accounts Receivable and Allowance for Doubtful Accounts	6 Months Ended
Jun. 30, 2018
Allowance For Doubtful Accounts And Unbilled Services [Abstract]
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Timing of revenue recognition often differs from the timing of billing to our customers. Generally, we transfer goods or services to a customer before the customer pays consideration or payment is due. If we have an unconditional right to invoice and receive payment for goods or services already provided, we record billed and unbilled receivables on our Condensed Consolidated Balance Sheets. Payment terms and conditions vary depending on the jurisdiction, market and type of service and whether regulatory or other third-party approvals are required. In addition, contracts may be negotiated per the client’s request, or at times we are asked to execute contracts in a form provided by customers that might include different terms. Our standard contract terms generally include a requirement of payment within 30 days where no contingencies exist. We record adjustments to the allowance for doubtful accounts and unbilled services as a reduction in revenues when there are changes in estimates of fee reductions, such as those fee reductions imposed by bankruptcy courts and other regulatory institutions for both billed and unbilled receivables. The allowance for doubtful accounts and unbilled services is also adjusted after the related work has been billed to the client and we discover that collectability is not reasonably assured. These adjustments are recorded to “Selling, general and administrative expenses” on the Condensed Consolidated Statements of Comprehensive Income. Our bad debt expense totaled $3.0 million and $8.7 million for the three and six months ended June 30, 2018, respectively, and $2.4 million and $6.0 million for the three and six months ended June 30, 2017, respectively.

Accounts Receivable and Allowance for Doubtful Accounts

Timing of revenue recognition often differs from the timing of billing to our customers. Generally, we transfer goods or services to a customer before the customer pays consideration or payment is due. If we have an unconditional right to invoice and receive payment for goods or services already provided, we record billed and unbilled receivables on our Condensed Consolidated Balance Sheets. Payment terms and conditions vary depending on the jurisdiction, market and type of service and whether regulatory or other third-party approvals are required. In addition, contracts may be negotiated per the client’s request, or at times we are asked to execute contracts in a form provided by customers that might include different terms. Our standard contract terms generally include a requirement of payment within 30 days where no contingencies exist.

We record adjustments to the allowance for doubtful accounts and unbilled services as a reduction in revenues when there are changes in estimates of fee reductions, such as those fee reductions imposed by bankruptcy courts and other regulatory institutions for both billed and unbilled receivables. The allowance for doubtful accounts and unbilled services is also adjusted after the related work has been billed to the client and we discover that collectability is not reasonably assured. These adjustments are recorded to “Selling, general and administrative expenses” on the Condensed Consolidated Statements of Comprehensive Income. Our bad debt expense totaled $3.0 million and $8.7 million for the three and six months ended June 30, 2018, respectively, and $2.4 million and $6.0 million for the three and six months ended June 30, 2017, respectively.