Shared-Based Compensation - Summary of Number of Awards Granted and Grand Date Fair Value (Detail) shares in Thousands	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant Date Fair Value (in USD per share)	$ 7.93
TSR Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted in fair values (in shares) | shares	136
Grant Date Fair Value (in USD per share)	$ 9.28
ROIC Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted in fair values (in shares) | shares	174
Grant Date Fair Value (in USD per share)	$ 7.93