Debt Obligations, Debt Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Scheduled Maturities of Debt [Abstract]
2021	$ 1,325.0
2022	1,400.0
2023	1,250.0
2024	850.0
2025	1,150.0
Thereafter	24,171.4
Total	30,146.4	$ 27,878.4
Senior Notes [Member]
Scheduled Maturities of Debt [Abstract]
2021	1,325.0
2022	1,400.0
2023	1,250.0
2024	850.0
2025	1,150.0
Thereafter	21,525.0
Total	27,500.0
Junior Subordinated Notes [Member]
Scheduled Maturities of Debt [Abstract]
2021	0.0
2022	0.0
2023	0.0
2024	0.0
2025	0.0
Thereafter	2,646.4
Total	$ 2,646.4

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
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-Paragraph 3
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