Schedule I - Condensed Financial Information of Registrant - Parent Company Only, Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Other assets	$ 3,145	$ 2,443
Total assets	82,243	78,316
LIABILITIES AND SHAREHOLDERS' EQUITY
Total liabilities	60,313	56,930
Shareholders' equity	19,119	18,518
Total liabilities and equity	82,243	78,316
Loews Corporation [Member]
ASSETS
Current assets, principally investment in short term instruments	2,550	2,050
Investments in securities	734	1,112
Investments in capital stocks of subsidiaries, at equity	18,123	17,556
Other assets	24	402
Total assets	21,431	21,120
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities	77	109
Long term debt	1,779	1,778
Deferred income tax and other	456	715
Total liabilities	2,312	2,602
Shareholders' equity	19,119	18,518
Total liabilities and equity	$ 21,431	$ 21,120