Number of shares that have been repurchased and retired during the period.

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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

Subsequent Event (Details) - $ / shares	1 Months Ended	2 Months Ended	7 Months Ended	10 Months Ended
Subsequent Event (Details) - $ / shares	Nov. 04, 2015	Feb. 18, 2015	Sep. 30, 2015	Dec. 31, 2014
Subsequent Event [Line Items]
Stock Repurchased and Retired During Period, Shares		335,251	655,178	910,990
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock Repurchased and Retired During Period, Shares	88,266
Stock Repurchased and Retired During Period, Average Price Per Share	$ 34.04