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Consolidated Statement of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Adjustment to pension benefit liability, taxes	$ 9	$ 10	$ 10	$ 7	$ 6	$ 7

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