Subsequent Events (Details) - $ / shares		12 Months Ended
	Jan. 29, 2016	Dec. 31, 2015
Class A Stock
Subsequent Event [Line Items]
Date of announcement of dividend		Jan. 29, 2016
Date of payment of dividend		Feb. 26, 2016
Date of record of dividend		Feb. 12, 2016
Subsequent Events | Class A Stock
Subsequent Event [Line Items]
Quarterly dividend payable amount per share	$ 0.11
Subsequent Events | Class B Stock
Subsequent Event [Line Items]
Quarterly dividend payable amount per share	$ 0.11