Segment Data (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 segment	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of business segments	2
Percentage of revenue generated from the foreign countries	7.40%	5.70%	3.40%
Percentage of total assets in the foreign countries	15.30%	12.20%
Brazil [Member]
Segment Reporting Information [Line Items]
Cash held outside United States		$ 178.1