Stockholders' Equity (Narrative) (Details) (USD $)	3 Months Ended			0 Months Ended			0 Months Ended			3 Months Ended		3 Months Ended		0 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Jul. 23, 2012 Class A Common Stock [Member]	Mar. 31, 2013 Class A Common Stock [Member]	Dec. 31, 2012 Class A Common Stock [Member]	Aug. 24, 2012 Class B Common Stock [Member]	Mar. 31, 2013 Class B Common Stock [Member]	Dec. 31, 2012 Class B Common Stock [Member]	Mar. 31, 2013 Restricted Common Class B [Member]	Aug. 24, 2012 Restricted Common Class B [Member]	Mar. 31, 2013 Minimum [Member]	Mar. 31, 2013 Maximum [Member]	Aug. 01, 2012 2012 Offering [Member] Class B Common Stock [Member]
Stockholders Equity [Line Items]
Common stock, par value				$ 0.01	$ 0.01	$ 0.01		$ 0.01	$ 0.01
Reverse stock split				1-for-2 reverse stock split
Common stock, voting rights per share	one vote with respect to all matters voted upon by our Class A and Class B common stockholders
Preferred stock, par value	$ 0.01		$ 0.01
Common stock, shares issued					11,657,563	11,657,563	503,226	4,512,225	4,465,725		312,499			3,650,000
Net proceeds from sale of shares							$ 6,500,000							$ 46,300,000
Repayments of mortgage debt														45,300,000
Common stock, shares outstanding					11,657,563	11,657,563		4,512,225	4,465,725
Vesting period										10 years		3 years	10 years
Grant date fair value of shares of restricted stock, vested	436,000	534,000
Recognized compensation cost related to restricted stock	267,000	144,000
Unrecognized compensation cost related to restricted stock	$ 7,600,000
Weighted average period for unrecognized compensation cost in years	7 years