Equity Offering (Details) (USD $)	1 Months Ended	6 Months Ended	38 Months Ended
Apr. 30, 2012	Jun. 30, 2012	Jun. 30, 2012
Equity Offering (Textual) [Abstract]
Gross Proceeds from Issuance of common stock	$ 75,000,000
Common stock, shares issued	3,750,000
Sale of stock, price per share	$ 20.00
Proceeds from sale of common stock, net of issuance costs	$ 70,000,000	$ 69,976,000	$ 199,335,000

The cash inflow from the additional capital contribution to the entity.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 19

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 18

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration