2. Revenue Recognition

On January 1, 2017, we adopted ASU 2014-09, “Revenue from Contracts with Customers” (“Topic 606”), applying the modified retrospective method to all contracts that were not completed as of that date. Results for reporting periods beginning after January 1, 2017 are presented under Topic 606, while prior period results are not adjusted and continue to be reported under the accounting standards in effect for the prior period. We recorded an increase to opening equity of $404,000 as of January 1, 2017 due to the cumulative impact of adopting Topic 606.

Disaggregation of revenue

The following table provides information about disaggregated revenue by primary geographical market and includes a reconciliation of the disaggregated revenue with reportable segments (in thousands):

	Three Months Ended March 31, 2018								Three Months Ended March 31, 2017
	Third-Party Software		Proprietary Software		Professional Engineering Service		Total		Third-Party Software		Proprietary Software		Professional Engineering Service		Total
Primary geographical markets:
North America	$	15,119	$	1,683	$	2,487	$	19,289	$	16,296	$	2,645	$	2,829	$	21,770
Europe		593		100		246		939		424		—		398		822
Asia		352		12		86		450		77		9		163		249
Total	$	16,064	$	1,795	$	2,819	$	20,678	$	16,797	$	2,654	$	3,390	$	22,841

Contract balances

We receive payments from customers based upon contractual billing schedules; accounts receivable is recorded when the right to consideration becomes unconditional. Contract assets include amounts related to our contractual right to consideration for completed performance objectives not yet invoiced and deferred contract acquisition costs, which are amortized along with the associated revenue. Contract liabilities include payments received in advance of performance under the contract and are realized with the associated revenue recognized under the contract. We had no asset impairment charges related to contract assets in the period.

Significant changes in the contract assets and the contract liabilities balances during the periods are as follows (in thousands):

	Three Months Ended March 31, 2018
	Contract Assets		Contract Liabilities⁽¹⁾
Revenue recognized that was included in the contract liability (deferred revenue) at December 31, 2017	$	—	$	2,214
Transferred to receivables from contract assets recognized at December 31, 2017		238		—
⁽¹⁾ Comprised of deferred revenue

Contract acquisition costs

We capitalize contract acquisition costs for contracts with life exceeding one year, as is more common with our DataV software bookings. Amortization of contract acquisition costs was $80,000 and $141,000 for the three months ended March 31, 2018 and 2017, respectively, and there was no impairment loss in relation to costs capitalized for either period.

For contracts that have a duration of less than one year, we apply a practical expedient and expense these costs when incurred.

Transaction price allocated to the remaining performance obligations

The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied at the end of the reporting period. The estimated revenues do not include contracts with original durations of one year or less, amounts of variable consideration attributable to royalties, or contract renewals that are unexercised as of March 31, 2018 (in thousands):

	Remainder of 2018		2019		2020		2021
Third-party software	$	89	$	50	$	14	$	—
Proprietary software		1,138		1,133		820		114
Professional engineering services		230		—		—		—

Practical expedients and exemptions

We generally expense sales commissions when incurred because the amortization period would have been less than one year. We record these costs within selling, general and administrative expenses.