Investments (Other Investments) (Details) - Air Touch [Member] $ in Billions	1 Months Ended	2 Months Ended
Apr. 30, 2020 USD ($) preferredStockSeries	Jun. 30, 2020 USD ($) preferredStockSeries
Schedule of Other Investments [Line Items]
Cash payments received upon redemption of preferred stock	$ 1.7
Number of preferred stock series (in series) \| preferredStockSeries	2	3
Cash payments for the redemption of redeemable preferred shares		$ 1.8

The cash inflow associated with the maturity, prepayments and calls (requests for early payments) of debt securities designated as held-to-maturity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26853-111562

Name:	us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration