Assets Held for Sale (Details) (Property and equipment, USD $) In Millions, unless otherwise specified	Mar. 31, 2013 Basel, Switzerland	Dec. 31, 2011 Vienna, Virginia
Assets Held for Sale
Long-lived assets held for sale	$ 8.3	$ 27.0

Long-lived assets that are held for sale apart from normal operations and anticipated to be sold in less than one year.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 45

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e1107-107759

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