Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Common stock, shares authorized	200,000,000
Common stock, shares issued	30,164,069
Common stock, shares outstanding	29,266,514	22,211,108
ClassACommonStockMember
Common stock, par value	0.01	0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	29,267,000	21,967,000
Common stock, shares outstanding	29,267,000	21,967,000
Restricted Class A CommonStock
Common stock, par value	0.01	0.01
Common stock, shares issued	0	244,000
Common stock, shares outstanding	0	244,000