Chapter 11 Proceedings - Summary of Liabilities Subject to Compromise (Parenthetical) (Detail)	Jan. 22, 2021
3.45% Senior Notes due 2023 [Member]
Liabilities Subject To Compromise [Line Items]
Interest rate of senior notes	3.45%
7.875% Senior Notes due 2025 [Member]
Liabilities Subject To Compromise [Line Items]
Interest rate of senior notes	7.875%
5.70% Senior Notes due 2039 [Member]
Liabilities Subject To Compromise [Line Items]
Interest rate of senior notes	5.70%
4.875% Senior Notes due 2043 [Member]
Liabilities Subject To Compromise [Line Items]
Interest rate of senior notes	4.875%

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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