Consolidated Statements of Changes In Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 1.45	$ 1.25
Stock issuance costs	$ 0	$ 0
Class A Common Stock
Statement of Stockholders' Equity [Abstract]
Stock Repurchased During Period, Shares	382,000	0
Class B Common Stock
Statement of Stockholders' Equity [Abstract]
Stock Repurchased and Retired During Period, Shares	0	0

Amount of decrease in additional paid in capital (APIC) resulting from direct costs associated with issuing stock. Includes, but is not limited to, legal and accounting fees and direct costs associated with stock issues under a shelf registration.

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- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

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-Publisher FASB
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- References

No definition available.

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- Definition

Number of shares that have been repurchased and retired during the period.

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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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-Publisher FASB
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-Topic 505
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