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Fair Value Measurements - Summary of Fair and Carrying Value of Debt Instruments (Details) - USD ($)	Dec. 31, 2020	Apr. 30, 2020	Dec. 31, 2019	Sep. 15, 2015
Debt Instrument
Notes payable, fair value	$ 8,515,900,000		$ 6,553,600,000
Senior Notes
Debt Instrument
Aggregate principal amount		$ 3,000,000,000.0
2.900% Senior Notes due September 15, 2020
Debt Instrument
Notes payable, fair value	$ 0		1,509,600,000
Interest rate on senior notes	2.90%
2.900% Senior Notes due September 15, 2020 | Senior Notes
Debt Instrument
Interest rate on senior notes	2.90%
Aggregate principal amount				$ 1,500,000,000
3.625% Senior Notes due September 15, 2022
Debt Instrument
Notes payable, fair value	$ 1,054,100,000		1,038,900,000
Interest rate on senior notes	3.625%
Aggregate principal amount	$ 1,000,000,000.0
3.625% Senior Notes due September 15, 2022 | Senior Notes
Debt Instrument
Interest rate on senior notes	3.625%
4.050% Senior Notes due September 15, 2025
Debt Instrument
Notes payable, fair value	$ 2,003,100,000		1,897,200,000
Interest rate on senior notes	4.05%
Aggregate principal amount	$ 1,750,000,000
4.050% Senior Notes due September 15, 2025 | Senior Notes
Debt Instrument
Interest rate on senior notes	4.05%
2.250% Senior Notes due May 1, 2030
Debt Instrument
Notes payable, fair value	$ 1,557,200,000		0
2.250% Senior Notes due May 1, 2030 | Senior Notes
Debt Instrument
Interest rate on senior notes	2.25%	2.25%
Aggregate principal amount		$ 1,500,000,000
5.200% Senior Notes due September 15, 2045
Debt Instrument
Notes payable, fair value	$ 2,365,100,000		2,107,900,000
Interest rate on senior notes	5.20%
Aggregate principal amount	$ 1,750,000,000
5.200% Senior Notes due September 15, 2045 | Senior Notes
Debt Instrument
Interest rate on senior notes	5.20%
3.150% Senior Notes due May 1, 2050
Debt Instrument
Notes payable, fair value	$ 1,536,400,000		$ 0
3.150% Senior Notes due May 1, 2050 | Senior Notes
Debt Instrument
Interest rate on senior notes	3.15%	3.15%
Aggregate principal amount		$ 1,500,000,000

X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

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- Definition

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

+ References

Reference 1: 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 http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Fair value portion of notes payable.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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