The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

Commitments and Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 bbl	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2008
Commitments and Contingencies [Abstract]
Operating Leases, Rent Expense	$ 2.4	$ 1.8	$ 1.5
Restricted escrow funds' trust				15.0
Misallocated oil volumes	74,000
Value of misallocated oil volumes	6.9
Restricted escrow trust funds including accumulated interest				16.7
Escrow Deposit	$ 6.0