Preferred Stock (Details) (USD $)	6 Months Ended		12 Months Ended	0 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jul. 17, 2013 Series A Cumulative Redeemable Perpetual Preferred Stock [Member]	Apr. 10, 2013 Series A Cumulative Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2013 Series A Cumulative Redeemable Perpetual Preferred Stock [Member] Quarter
Class of Stock [Line Items]
Preferred stock issued (in shares)						250,000
Preferred stock, dividend rate (in hundredths)	9.50%		9.50%			9.50%
Preferred stock, par value (in dollars per share)	$ 1.00		$ 1.00			$ 1.00
Preferred stock, liquidation preference per share (in dollars per share)						$ 100.00
Preferred stock, dividend declared (in dollars per share)				$ 2.375	$ 1.79
Accumulated unpaid dividends						$ 594,000
Preferred stock, redemption date				Jul. 30, 2013		Apr. 30, 2018
Preferred stock, cash redemption price per share (in dollars per share)						$ 100
Net proceeds from the issuance of preferred stock	23,480,000	0				23,480,000
Underwriter discounts and related costs						$ 1,600,000
Period after change of control to redeem shares						120 days
Period of dividends to be in arrears before limited voting rights apply						6