CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Stockholders' Equity [Abstract]
Other comprehensive income (loss), defined benefit plan, transition asset (obligation), reclassification adjustment from AOCI, tax	$ 448	$ (328)	$ (101)
Dividend paid per sub-share (in USD per share)	$ 11.00	$ 10.00	$ 1.75
Special dividends paid per sub-share certificate (in dollars per share)		$ 16.00	$ 4.25