Consolidated Statements of Changes In Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock repurchased during period (in shares)	205,500		448,500
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.40	$ 0.35	$ 0.80	$ 0.70
Common Stock | Class A Common Stock
Stock repurchased during period (in shares)	205,500	0	448,500	0