Significant Accounting Policies Concentration Risks (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Sales [Member] | Revenue From Fixed Price Contracts [Member]
Concentration Risk [Line Items]
Concentration risk percentage	5.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk percentage	22.00%	26.00%