Condensed Consolidated Statements of Stockholders' Deficit (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Issuance of shares of AAG common stock pursuant to a public stock offering (in shares)	18,194,573
Purchase and retirement of common stock (in shares)		6,378,025
Dividends declared on common stock (in dollars per share)	$ 0	$ 0.10
Issuance of shares of common stock pursuant to employee stock plans (in shares)	1,700,380	1,062,052