v3.20.4
Additional Financial Information
 12 Months Ended
Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Additional Financial Information
NOTE 22. ADDITIONAL FINANCIAL INFORMATION

December 31,
Consolidated Balance Sheets20202019
Accounts payable and accrued liabilities:
Accounts payable$31,836 $29,640 
Accrued payroll and commissions2,988 3,126 
Current portion of employee benefit obligation1,415 1,528 
Accrued participations and residuals
2,708 2,852 
Accrued interest2,454 2,498 
Other7,631 6,312 
Total accounts payable and accrued liabilities$49,032 $45,956 

Consolidated Statements of Income202020192018
Advertising expense$5,253 $6,121 $5,100 
Interest expense incurred$8,048 $8,622 $8,450 
Capitalized interest(123)(200)(493)
Total interest expense$7,925 $8,422 $7,957 

Cash and Cash Flows We typically maintain our restricted cash balances for purchases and sales of certain investment securities and funding of certain deferred compensation benefit payments.

The following table summarizes cash and cash equivalents and restricted cash balances contained on our consolidated balance sheets:
December 31,
Cash and Cash Equivalents and Restricted Cash2020201920182017
Cash and cash equivalents$9,740 $12,130 $5,204 $50,498 
Restricted cash in Other current assets9 69 61 6 
Restricted cash in Other Assets121 96 135 428 
Cash and cash equivalents and restricted cash$9,870 $12,295 $5,400 $50,932 

The following table summarizes cash paid during the periods for interest and income taxes:
Consolidated Statements of Cash Flows202020192018
Cash paid (received) during the year for:
Interest$8,237 $8,693 $8,818 
Income taxes, net of refunds993 1,421 (354)
Spectrum acquisitions
1,613 1,576 521 

Noncash Investing and Financing Activities In connection with capital improvements and the acquisition of other productive assets, we negotiate favorable payment terms (referred to as vendor financing), which are reported as financing activities in our statements of cash flows when paid. We recorded $4,664 of vendor financing commitments related to capital investments in 2020, $2,632 in 2019 and $2,162 in 2018.
Labor Contracts As of January 31, 2021, we employed approximately 230,000 persons. Approximately 37% of our employees are represented by the Communications Workers of America (CWA), the International Brotherhood of Electrical Workers (IBEW) or other unions. After expiration of the agreements, work stoppages or labor disruptions may occur in the absence of new contracts or other agreements being reached. There are no significant contracts expiring in 2021. A contract covering approximately 14,000 Mobility employees in 36 states and the District of Columbia that was set to expire in February 2021 was extended until February 2022. A contract covering approximately 10,000 Mobility employees in nine Southeast states that was set to expire in February 2022 was extended until February 2023.