Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Share-Based Compensation Plans - Performance Share Awards Narrative (Details) - Performance-based Awards [Member] - shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
2010 Leadership Performance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)	1.6
Other Performance Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)		0.2
2009 Leadership Performance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)		0.8
2008 Leadership Performance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)			0.6
2006 Performance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)			0.1