Preferred Stock (Details) (USD $)	12 Months Ended	0 Months Ended					12 Months Ended	0 Months Ended
	Dec. 31, 2013	Oct. 06, 2014	Jul. 07, 2014	Apr. 09, 2014	Jan. 07, 2014	Feb. 21, 2013	Dec. 31, 2014	Aug. 01, 2013	Jan. 08, 2015
Class of Stock [Line Items]
Net proceeds from the issuance of preferred stock	$ 53,333,000
Series A Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock issued						250,000
Preferred stock, dividend rate						9.50%
Preferred stock, par value						$ 1.00
Preferred stock, liquidation preference per share						$ 100.00
Preferred stock, dividend declared		$ 2.375	$ 2.375	$ 2.375	$ 2.375
Accumulated unpaid dividends							0
Preferred stock, redemption date							Apr. 30, 2018
Cash redemption price (in dollars per share)							$ 100.00
Net proceeds from the issuance of preferred stock	23,400,000
Underwriter discounts and related costs	1,600,000
Period after change of control to redeem shares							120 days
Series B Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock issued								316,250
Preferred stock, dividend rate								9.00%
Preferred stock, par value								$ 1.00
Preferred stock, liquidation preference per share								$ 100.00
Shares sold pursuant to over-allotment option granted to underwriters for offering								41,250
Preferred stock, dividend declared		$ 2.25	$ 2.25	$ 2.25	$ 2.25
Accumulated unpaid dividends							0
Preferred stock, redemption date							Oct. 30, 2018
Cash redemption price (in dollars per share)							$ 100.00
Net proceeds from the issuance of preferred stock	30,000,000
Underwriter discounts and related costs	$ 1,700,000
Period after change of control to redeem shares							120 days
Subsequent Event [Member] | Series A Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend declared									$ 2.375
Subsequent Event [Member] | Series B Cumulative Redeemable Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend declared									$ 2.25