Profit Sharing Plan (Details) (Profit Sharing Plan [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Profit Sharing Plan [Member]
Profit Sharing Plan [Line Items]
Requisite service period (in months)	12M
Requisite service hours	1,000
Compensation expense	$ 502	$ 357	$ 183