Subsequent Event (Details)	Nov. 21, 2013 USD ($)	Nov. 07, 2013 GBP (£)
Subsequent Events [Abstract]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	$ 87,000,000
business combination, potential per share cost (in GBP)		20.75
business combination, potential consideration to be transfered (in GBP)		£ 172,500,000

Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant