Fair value measurement (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

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, 2019
	Level 1		Level 2		Level 3		Total
Assets:
Cash and other	$	1,395	$	—	$	—	$	1,395
Corporate stock	111,193		—		—		111,193
Interest in registered investment companies	48,221		—		—		48,221
Total	$	160,809	$	—	$	—	$	160,809
Pension plan investments valued using net asset value as a practical expedient:
Common collective trust - equities							$	111,385
Common collective trust - fixed income							185,844
Hedge funds							17,125
Partnership/joint venture interests							4,572
Total fair value of plan assets							$	479,735

Fair value measurement as of Dec. 31, 2018
	Level 1		Level 2		Level 3		Total
Assets:
Cash and other	$	958	$	—	$	—	$	958
Corporate stock	83,489		—		—		83,489
Interest in registered investment companies	39,007		—		—		39,007
Total	$	123,454	$	—	$	—	$	123,454
Pension plan investments valued using net asset value as a practical expedient:
Common collective trust - equities							$	104,993
Common collective trust - fixed income							158,580
Hedge funds							16,126
Partnership/joint venture interests							4,397
Total fair value of plan assets							$	407,550