Schedule I - Condensed Financial Information of Registrant, Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities [Abstract]
Net income (loss)	$ 1,703	$ (1,291)	$ 871
Adjustments to reconcile net income to net cash provided (used) by operating activities [Abstract]
Equity method investees	(74)	102	20
Provision for deferred income taxes	213	(235)	70
Changes in operating assets and liabilities, net [Abstract]
Receivables	(1,409)	(425)	114
Trading securities	(49)	(571)	(494)
Net cash flow provided by operating activities	2,623	1,745	1,741
Investing Activities [Abstract]
Change in investments, primarily short term	(141)	427	(57)
Net cash flow used by investing activities	(1,187)	(1,414)	(671)
Financing Activities [Abstract]
Dividends paid	(65)	(70)	(76)
Purchases of treasury shares	(1,136)	(923)	(1,051)
Issuance of debt	1,199	2,659	2,076
Other	(12)	(2)	(16)
Net cash flow (used) provided by financing activities	(1,289)	(198)	(1,144)
Net change in cash	143	142	(69)
Cash, beginning of year	478	336	405
Cash, end of year	621	478	336
Loews Corporation
Operating Activities [Abstract]
Net income (loss)	1,578	(931)	932
Adjustments to reconcile net income to net cash provided (used) by operating activities [Abstract]
Equity method investees	(820)	834	36
Loss on deconsolidation	15	1,211
Provision for deferred income taxes	7	(196)	106
Changes in operating assets and liabilities, net [Abstract]
Receivables			1
Accounts payable and accrued liabilities	(48)	(38)	(29)
Trading securities	(69)	(566)	(478)
Other, net	82	44	36
Net cash flow provided by operating activities	745	358	604
Investing Activities [Abstract]
Investments in and advances to subsidiaries	385	(169)	183
Change in investments, primarily short term	72	326	326
Net cash flow used by investing activities	457	157	509
Financing Activities [Abstract]
Dividends paid	(65)	(70)	(76)
Purchases of treasury shares	(1,136)	(923)	(1,051)
Issuance of debt		495
Other	(4)	(5)	(5)
Net cash flow (used) provided by financing activities	(1,205)	(503)	(1,132)
Net change in cash	(3)	12	(19)
Cash, beginning of year	22	10	29
Cash, end of year	19	22	10
Cash dividends paid to Company by affiliates	$ 853	$ 947	$ 927