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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 |  |

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- 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 + Details
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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 + Details
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