Consolidated Statements of Stockholders' Equity (Parenthetical) (Preferred Stock)	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012
Preferred Stock
Redemption of preference shares	18,255	12,000

Number of stock bought back by the entity at the exercise price or redemption price.

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

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