Consolidated Statements of Changes In Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 1.60	$ 1.45	$ 1.25
Class A Common Stock
Statement of Stockholders' Equity [Abstract]
Stock repurchases (shares)	998,910	382,000
Cash dividends (in dollars per share)	$ 1.60	$ 1.45	1.25
Class B Common Stock
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 1.60	$ 1.45	$ 1.25