Stockholders' Equity - Additional Information (Details) (USD $)	1 Months Ended	6 Months Ended		1 Months Ended
May 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Mar. 31, 2013 Follow-on public offering [Member]
Class of Stock [Line Items]
Dividend rate of Series A cumulative redeemable preferred stock		8.625%
Common stock, shares issued		36,880,410	28,044,106	8,805,000
Common stock, offering price per share				$ 16.90
Net proceeds from the offering				$ 148,318,000
ATM Equity Offering, maximum authorized amount	$ 100,000,000

Common Stock Offering, Maximum Authorized Amount

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- Definition

Net Proceeds From Issuance Of Initial Public Offering After Deducting Underwriting Discounts And Commissions And Offering Costs

+ References

No definition available.

+ Details

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

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- Definition

The percentage rate used to calculate dividend payments on preferred stock.

+ References

No definition available.

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- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section H

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