Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

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

- Definition

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_DividendsPayableAmountPerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

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

- Definition

Aggregate dividends declared during the period for each share of preferred stock outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_PreferredStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesAPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesDPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesEPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DividendsAxis=us-gaap_DividendDeclaredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Dividends - Narrative) (Details) - USD ($)				3 Months Ended													12 Months Ended
	Dec. 01, 2019	Aug. 31, 2019	Mar. 05, 2019	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Estimated aggregate dividend payment					$ 406,000,000	$ 413,000,000	$ 419,000,000	$ 405,000,000	$ 415,000,000	$ 419,000,000	$ 428,000,000	$ 416,000,000	$ 422,000,000	$ 427,000,000	$ 431,000,000	$ 437,000,000	$ 1,643,000,000	$ 1,678,000,000	$ 1,717,000,000
Series A Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock, dividend rate	$ 0.253	$ 0	$ 0.250		$ 0	$ 0.253	$ 0.261	$ 0	$ 0.253	$ 0.256	$ 0.256	$ 0.250	$ 0.253	$ 0.256	$ 0.256	$ 0.250	$ 1.017	$ 1.015	$ 1.015
Preferred stock, dividends	$ 6,000,000	$ 0	$ 6,000,000		$ 0	$ 6,000,000	$ 6,000,000	$ 0	$ 6,000,000	$ 6,000,000	$ 7,000,000	$ 6,000,000	$ 6,000,000	$ 6,000,000	$ 7,000,000	$ 6,000,000	$ 24,000,000	$ 25,000,000	$ 25,000,000
Series D Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock, dividend rate	$ 0	$ 29.375	$ 0		$ 0	$ 0	$ 0	$ 29.375	$ 0	$ 28.233	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 58.750	$ 28.233	$ 0
Preferred stock, dividends	$ 0	$ 15,000,000	$ 0		$ 0	$ 0	$ 0	$ 15,000,000	$ 0	$ 14,000,000	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 30,000,000	$ 14,000,000	$ 0
Series E Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock, dividend rate	$ 0	$ 351.563	$ 0		$ 351.563	$ 0	$ 351.563	$ 351.563	$ 351.563	$ 394.531	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 1,406.252	$ 746.094	$ 0
Preferred stock, dividends	$ 0	$ 11,000,000	$ 0		$ 11,000,000	$ 0	$ 12,000,000	$ 11,000,000	$ 11,000,000	$ 12,000,000	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 45,000,000	$ 23,000,000	$ 0
Subsequent Event [Member]
Subsequent Event [Line Items]
Estimated aggregate dividend payment				$ 404,000,000
Subsequent Event [Member] \| Dividends Declared [Member] \| Series A Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock, dividend rate				$ 0.253
Preferred stock, dividends				$ 6,000,000
Subsequent Event [Member] \| Dividends Declared [Member] \| Series D Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock, dividend rate				$ 29.375
Preferred stock, dividends				$ 15,000,000
Subsequent Event [Member] \| Dividends Declared [Member] \| Series E Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock, dividend rate				$ 351.563
Preferred stock, dividends				$ 11,000,000
Subsequent Event [Member] \| Dividends Declared [Member] \| Common Stock
Subsequent Event [Line Items]
Approved annual dividend, amount per share				$ 0.44