Revenues Revenues	12 Months Ended
Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenues	Revenues Revenues recognized during the current period may include revenues recognized from performance obligations satisfied or partially satisfied in previous periods. This primarily occurs when the estimated transaction price has changed based on a re-assessment of the expected probability of achieving the agreed-upon outcome for our performance-based and contingent arrangements, resulting in a catch-up adjustment for service provided in previous periods. The aggregate amount of revenues recognized related to the catch-up adjustment due to a change in the transaction price during the year ended December 31, 2018 was $16.1 million. Unfulfilled performance obligations represent the remaining contract transaction prices allocated to the performance obligations that are unsatisfied, or partially unsatisfied, and therefore revenues have not yet been recorded. Unfulfilled performance obligations primarily consist of the remaining fees not yet recognized under our proportional performance method for both our fixed fee arrangements and the portion of performance-based and contingent arrangements that we have deemed probable. As of December 31, 2018, the aggregate amount of the transaction price allocated to unfulfilled performance obligations was $8.8 million, and we expect to recognize the majority of the related revenues over the next 24 months. We elected to utilize the optional exemption to exclude from this disclosure fixed fee and performance-based and contingent arrangements with an original expected duration of one year or less and to exclude our time and expense arrangements for which revenues are recognized using the right-to-invoice practical expedient. Contract assets are defined as assets for which we have recorded revenue because we determined that it is probable that we will earn a performance-based or contingent fee, but we are not yet entitled to receive our fees because certain events, such as completion of the measurement period or client approval, must occur. The contract asset balance was $2.4 million as of December 31, 2018 and immaterial as of December 31, 2017. Contract liabilities are defined as liabilities incurred when we have received consideration from a client but have not yet performed the agreed-upon services. This may occur when we receive advance billings before delivery and acceptance of software licenses in our Technology segment and when clients pay us upfront fees before we begin work for them. The contract liability balance was immaterial as of December 31, 2018 and December 31, 2017.

Revenues

Revenues recognized during the current period may include revenues recognized from performance obligations satisfied or partially satisfied in previous periods. This primarily occurs when the estimated transaction price has changed based on a re-assessment of the expected probability of achieving the agreed-upon outcome for our performance-based and contingent arrangements, resulting in a catch-up adjustment for service provided in previous periods. The aggregate amount of revenues recognized related to the catch-up adjustment due to a change in the transaction price during the year ended December 31, 2018 was $16.1 million.

Unfulfilled performance obligations represent the remaining contract transaction prices allocated to the performance obligations that are unsatisfied, or partially unsatisfied, and therefore revenues have not yet been recorded. Unfulfilled performance obligations primarily consist of the remaining fees not yet recognized under our proportional performance method for both our fixed fee arrangements and the portion of performance-based and contingent arrangements that we have deemed probable. As of December 31, 2018, the aggregate amount of the transaction price allocated to unfulfilled performance obligations was $8.8 million, and we expect to recognize the majority of the related revenues over the next 24 months. We elected to utilize the optional exemption to exclude from this disclosure fixed fee and performance-based and contingent arrangements with an original expected duration of one year or less and to exclude our time and expense arrangements for which revenues are recognized using the right-to-invoice practical expedient.

Contract assets are defined as assets for which we have recorded revenue because we determined that it is probable that we will earn a performance-based or contingent fee, but we are not yet entitled to receive our fees because certain events, such as completion of the measurement period or client approval, must occur. The contract asset balance was $2.4 million as of December 31, 2018 and immaterial as of December 31, 2017.

Contract liabilities are defined as liabilities incurred when we have received consideration from a client but have not yet performed the agreed-upon services. This may occur when we receive advance billings before delivery and acceptance of software licenses in our Technology segment and when clients pay us upfront fees before we begin work for them. The contract liability balance was immaterial as of December 31, 2018 and December 31, 2017.