Capital Stock (Details) - USD ($) $ in Thousands		9 Months Ended
	Apr. 03, 2015	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Class of Stock [Line Items]
Payments for Repurchase of Common Stock		$ 20,548	$ 9,736
Class A Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding		21,583,324		21,928,932
Stock Repurchased and Retired During Period, Shares		765,875	325,418
Payments for Repurchase of Common Stock		$ 19,921	$ 8,143
Stock Repurchase Program, Remaining Authorized Repurchase Amount		1,000,000
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
Class B Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding		23,761,683		23,859,483