Consolidated Statement of Changes in Stockholders' Equity (Parenthetical) (Parentheticals)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Common shares issued from treasury stock for stock-based compensation (in shares)	2,257,067	4,522,294
Common shares repurchased (in shares)	4,779,963us-gaap_TreasuryStockSharesAcquired	18,110,735us-gaap_TreasuryStockSharesAcquired

Number of shares that have been repurchased during the period and are being held in treasury.

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 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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

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