Condensed Consolidated Statements of Stockholders' Deficit (Parenthetical) - USD ($) $ in Thousands		3 Months Ended
		Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Jun. 30, 2019
Statement Of Stockholders Equity Parenthetical [Abstract]
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, tax	[1]	$ 0	$ 0	$ 0	$ 0
Other comprehensive income (loss), tax	[1]	$ 0	$ 0	$ 0	$ 0
Dividends declared and paid per common share (in dollars per share)	[1]			$ 0.04	$ 0.04

[1] As adjusted; refer to Note 1.