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Capital Stock (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 03, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Payments for Repurchase of Common Stock	$ 15,264	$ 3,159
Class A Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	21,596,056			21,928,932
Stock Repurchased and Retired During Period, Shares	565,875	100,355,000
Payments for Repurchase of Common Stock	$ 14,674	$ 2,538
Stock Repurchase Program, Remaining Authorized Repurchase Amount	434,125
Class B Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	23,833,412			23,859,483
Subsequent Event [Member] \| Class A Common Stock \| 2015 Equity Compensation Plan
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized			2,000,000