Business Segment, Geographic and Major Customer Information - Major Customers (Details)	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Customer A [Member]
Summary of revenue from major costumers
Percentage of revenue by major customers	17.50%		15.80%
Customer B [Member]
Summary of revenue from major costumers
Percentage of revenue by major customers	10.00%	[1]	11.10%

[1] This customer did not account for more than 10% of revenue.