Consolidated Statements of Changes In Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Stock repurchased during period (in shares)	243,000
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.40	$ 0.35
Common Stock \| Class A Common Stock
Stock repurchased during period (in shares)	243,000	0

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Balance Type:	na
Period Type:	duration