Stockholder's Equity (Schedule Of Cash Dividends Paid Or Payable Per Share) (Details) (USD $)	3 Months Ended
Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013
Common Stock [Member]
Dividends Payable [Line Items]
Dividend per Share, Common stock	$ 0.160000	$ 0.140000	$ 0.140000	$ 0.130000	$ 0.130000	$ 0.130000	$ 0.130000	$ 0.120000
Declaration Date	Nov. 04, 2014	Aug. 08, 2014	May 09, 2014	Feb. 19, 2014	Nov. 05, 2013	Aug. 06, 2013	May 07, 2013	Feb. 19, 2013
Record Date	Dec. 31, 2014	Oct. 07, 2014	Jul. 07, 2014	Apr. 07, 2014	Dec. 31, 2013	Oct. 07, 2013	Jul. 05, 2013	Apr. 05, 2013
Date Paid	Jan. 14, 2015	Oct. 21, 2014	Jul. 21, 2014	Apr. 21, 2014	Jan. 14, 2014	Oct. 21, 2013	Jul. 19, 2013	Apr. 19, 2013
Preferred Stock [Member]
Dividends Payable [Line Items]
Dividend per Share, Preferred stock	$ 0.484375	$ 0.484375	$ 0.484375	$ 0.484375	$ 0.484375	$ 0.484375	$ 0.484375	$ 0.484375
Declaration Date	Nov. 04, 2014	Aug. 08, 2014	May 09, 2014	Feb. 19, 2014	Nov. 05, 2013	Aug. 06, 2013	May 07, 2013	Feb. 19, 2013
Record Date	Dec. 12, 2014	Sep. 12, 2014	Jun. 11, 2014	Mar. 10, 2014	Dec. 11, 2013	Sep. 11, 2013	Jun. 11, 2013	Mar. 11, 2013
Date Paid	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jul. 01, 2013	Mar. 31, 2013

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-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

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

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