Fair value measurement (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Pension Plan Assets by Level within Fair Value Hierarchy

The below fair value tables relate to our TRP pension plan assets (in thousands):

Pension Plan Assets
Fair value measurement as of Dec. 31, 2022
	Level 1	Level 2	Level 3	Total
Assets:
Pension plan investments valued using net asset value as a practical expedient:
Common collective trust - equities				$	54,917
Common collective trust - fixed income				329,821
Partnership/joint venture interests				267
Total fair value of plan assets				$	385,005

Fair value measurement as of Dec. 31, 2021
	Level 1		Level 2		Level 3		Total
Assets:
Cash and other	$	544	$	—	$	—	$	544
Corporate stock	25,324		—		—		25,324
Interest in registered investment companies	6,239		—		—		6,239
Total	$	32,107	$	—	$	—	$	32,107
Pension plan investments valued using net asset value as a practical expedient:
Common collective trust - equities							$	22,356
Common collective trust - fixed income							465,842
Hedge fund							19,156
Partnership/joint venture interests							2,297
Total fair value of plan assets							$	541,758