Restricted Stock (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Restricted Stock [Abstract]
Shares of class B restricted stock issued (in shares)	20,119	19,558
Value per share of class B restricted stock issued (in dollars per share)	$ 21.87	$ 22.5
Total value of shares issued	$ 440	$ 440