Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Trade accounts receivable, allowances for doubtful accounts	$ 365	$ 736
Intangible assets, accumulated amortization	$ 38,846	$ 36,627
Partners' capital:
Common units issued (in shares)	141,995,028	141,237,462
Common units outstanding (in shares)	141,995,028	141,237,462