Concentrations of Credit and Liquidity Risk (Details) (ClearPoint, USD $) In Thousands, unless otherwise specified						6 Months Ended
Jun. 30, 2012	Dec. 31, 2011	Jul. 31, 2012 Credit Facility No. 3	Jun. 30, 2012 Credit Facility No. 3	Dec. 31, 2011 Credit Facility No. 3	Jun. 30, 2012 Borrowings Risk related to lenders item	Jun. 30, 2012 Borrowings Risk related to lenders Credit Facility No. 3
Concentrations of Credit and Liquidity Risk
Number of Lenders to Finance Activities						2
Facility Limit	$ 150,000	$ 300,000	$ 45,000	$ 75,000	$ 100,000		$ 75,000

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant