Shared-Based Compensation - Summary of Number of Awards Granted and Grand Date Fair Value (Detail) shares in Thousands	9 Months Ended
	Sep. 30, 2021 $ / shares shares
TSR Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option equity instruments, outstanding (in shares) | shares	142
Grant Date Fair Value (in dollars per share) | $ / shares	$ 8.58
ROIC Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option equity instruments, outstanding (in shares) | shares	172
Grant Date Fair Value (in dollars per share) | $ / shares	$ 7.20