Shareholders' Equity - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013
Shareholders Equity [Line Items]
Repurchase of stock	9.6	4.9
Repurchase of aggregate equity stock	$ 83
Purchase of Loews treasury stock	415	218
Diamond Offshore [Member]
Shareholders Equity [Line Items]
Repurchase of stock	1.9
Repurchase of aggregate equity stock	88
Decrease in Additional paid-in capital	$ 8
Diamond Offshore [Member] \| Minimum [Member]
Shareholders Equity [Line Items]
Subsidiary ownership percentage	50.40%
Diamond Offshore [Member] \| Maximum [Member]
Shareholders Equity [Line Items]
Subsidiary ownership percentage	51.10%

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Amount of other increase (decrease) in additional paid in capital (APIC).

+ References

No definition available.

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- Definition

Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 23

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569655-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 24

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4616395-111683

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- Definition

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

+ References

No definition available.

+ Details

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

+ Details

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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 45

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-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

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