CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Cumulative dividends declared per common share (in dollars per share)	$ 0.12	$ 0.01	$ 0.24	$ 0.02	$ 0.04