Supplemental Information (Expenses) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary of expenses in statements of operations
Research and development	$ 62,300,000	$ 60,700,000	$ 53,700,000
Advertising, promotions and marketing	42,500,000	41,900,000	45,200,000
Cooperative advertising expenditures	13,700,000	13,100,000	10,900,000
Rent expense	53,500,000	50,500,000	53,500,000
Discontinued Operations [Member]
Summary of expenses in statements of operations
Advertising, promotions and marketing	0	0	4,100,000
Rent expense	$ 0	$ 0	$ 4,500,000