Benefit Plans (Details 4)				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Unvested Options [Member]
Unvested options:
Outstanding at beginning of year, shares	581,888	587,342	463,642	269,875
Granted				0
Forfeited				(888)
Vested during the period				(82,332)
Outstanding at end of year, shares	581,888	587,342	463,642	186,655