Accounts Receivable Securitization Program (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Accounts Receivable Securitization Program (Textual) [Abstract]
Maximum purchase limit for receivable interests under Accounts Receivable Securitization Program	$ 125
Amount available for accounts receivable securitization program	92.0	91.0
Level of eligible assets available under accounts receivable securitization program	lower than $125 million
Amount outstanding under accounts receivable securitization program	$ 0	$ 0
Accounts receivable securitization program expiration date	2012-12
Bank financing commitment expiration date	Dec. 02, 2011