Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Dividends on common stock and dividend equivalents declared (in dollars per share)	$ 0.77	$ 0.73
Series E Preferred Stock [Member]
Dividends on preferred stock (in dollars per share)	$ 1,200	$ 1,200

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

Reference 1: 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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Period Type:	duration