Shareholders' Equity (Schedule of Stock by Class) (Details)	Sep. 30, 2016 stock_class $ / shares shares	Dec. 31, 2015 $ / shares shares
Class of Stock [Line Items]
Number of classes of common stock | stock_class	3
Class A stock [Member]
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares	$ 0.025	$ 0.025
Authorized Shares	80,000,000	80,000,000
Outstanding	36,800,000	35,400,000
Treasury	3,200,000	4,600,000
Total Issued Shares	40,000,000	40,000,000
Class B stock [Member]
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares	$ 0.025	$ 0.025
Authorized Shares	80,000,000	80,000,000
Outstanding	14,200,000	14,200,000
Treasury	800,000	800,000
Total Issued Shares	15,000,000	15,000,000
Class C stock [Member]
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares	$ 0.025	$ 0.025
Authorized Shares	20,000,000	20,000,000
Outstanding	0	0
Treasury	500,000	500,000
Total Issued Shares	500,000	500,000