Subsequent Events (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		1 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Apr. 24, 2013 EMC Information Infrastructure Pivotal	Apr. 24, 2013 VMware Pivotal	Apr. 24, 2013 EMC Pivotal	Apr. 30, 2013 Limited Partner Pivotal	Apr. 24, 2013 Limited Partner Pivotal
Subsequent Event [Line Items]
Payments to Acquire Interest	$ 94,737	$ 0				$ 105,000
Ownership Interest Percentage			62.00%	28.00%	84.00%		10.00%

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 17

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_PaymentsToAcquireInterestInJointVenture
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration