Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Common stock dividend declared	$ 0.25	$ 0.25	$ 0.25
Common stock dividend paid	$ 0.25	$ 0.25	$ 0.25
Treasury stock repurchased, shares	21.5	20.3	4.8
Purchase of Loews treasury stock	$ 1,059	$ 1,011	$ 237
Treasury stock retired, shares	21.4