Condensed Consolidated Statements of Cash Flows (unaudited) (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended
Jun. 30, 2014
Statement Of Cash Flows [Abstract]
Shares issued as consideration under an equity financing agreement	329,131
Right to sell of common stock	$ 30

Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

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

Name:	us-gaap_SharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant