4. SUPPLEMENTAL CONSOLIDATED FINANCIAL STATEMENT INFORMATION

Disaggregated Revenues

The Company has one line of business, acquiring and processing seismic data in North America. Our chief operating decision maker (President, Chief Executive Officer and Chairman of the Board) makes operating decisions and assesses performance based on the Company as a whole. Accordingly, the Company is considered to be in a single reportable segment. The following table presents the Company’s operating revenues (unaudited and in thousands) disaggregated by geographic region:


	Three Months Ended March 31,
		2019		2018
Operating Revenues
United States	$	37,636	$	37,777
Canada		13,528		12,103
Total	$	51,164	$	49,880

Deferred Costs (in thousands)

The opening balance of deferred cost was $6,994 and $2,991 at January 1, 2019 and 2018, respectively. The Company’s prepaid expenses and other current assets at March 31, 2019 and 2018 included deferred costs incurred to fulfill contracts with customers of $3,997 and $4,688, respectively.

Deferred costs at March 31, 2019 compared to January 1, 2019 decreased primarily as a result of the completion of several projects during the first quarter of 2019 that had significant deferred fulfillment costs at January 1, 2019. Deferred cost at March 31, 2018 compared to January 1, 2018 increased primarily as a result of new projects for clients with significant deferred fulfillment costs at March 31, 2018.

The amount of total deferred costs amortized for the first quarter of 2019 and 2018 was $12,905 and $6,999, respectively. There were no material impairment losses incurred during these periods.

Deferred Revenue (in thousands)

The opening balance of deferred revenue was $10,501 and $6,314 at January 1, 2019 and 2018, respectively. The Company’s deferred revenue at March 31, 2019 and 2018 was $5,675 and $5,833, respectively.

Deferred revenue at March 31, 2019 compared to January 1, 2019 decreased primarily as a result of completing projects for clients with large prepayments for third party reimbursables. Deferred revenue at March 31, 2018 compared to January 1, 2018 remained fairly consistent.

Revenue recognized for the first quarter of 2019 and 2018 that was included in the contract liability balance at the beginning of 2019 and 2018 was $6,893 and $3,683, respectively.