Common Stock (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 Executive Officer [Member] Class A Nonvoting Common Stock [Member]	Jun. 30, 2011 Executive Officer [Member] Class A Nonvoting Common Stock [Member]	Jun. 30, 2012 Employee Stock [Member] Class A Nonvoting Common Stock [Member]
Common Stock [Line Items]
Common stock, shares issued		155,925	174,825	9,680
Common stock				$ 44,000
Options exercised	95,000
Realized value options exercised	136,000
Cash received for options exercised	$ 308,000