STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class A
Dividends declared (in dollars per share)	$ 2.773	$ 2.586	$ 2.4125
Class B
Dividends declared (in dollars per share)	$ 415.95	$ 387.9	$ 361.875