Shareholders' Equity (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Common Class A [Member]
Class of Stock [Line Items]
Common Stock, par value per share	$ 0.001	$ 0.001
Common Stock reserved for the conversion of Class B Common Stock and the exercise of stock options	3.5
Number of shares authorized to be repurchased	2.0
Common Class B [Member]
Class of Stock [Line Items]
Common Stock, par value per share	$ 0.001	$ 0.001