Consolidated Statement of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Adjustment to pension benefit liability, taxes	$ 7	$ 6	$ 7	$ 4	$ 5	$ 4