Earnings Per Share (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($) $ / shares shares	Sep. 30, 2020 USD ($) $ / shares shares	Sep. 30, 2021 USD ($) Vote $ / shares shares	Sep. 30, 2020 USD ($) $ / shares shares
Common Stock [Member]
Earnings Per Share [Abstract]
Percentage of earnings assumed to be distributed as dividends in earnings per share calculation			100.00%
Preferential dividend rate			105.00%
Number of votes per share | Vote			1
Numerator [Abstract]
Distributed earnings	$ 4,164	$ 3,423	$ 12,142	$ 9,475
Undistributed earnings	18,424	13,408	49,713	21,624
Basic	22,588	16,831	61,855	31,099
Diluted	$ 24,233	$ 18,261	$ 66,497	$ 33,720
Denominator [Abstract]
Weighted average shares outstanding - basic (in shares) | shares	16,794	17,098	16,862	17,267
Assumed conversion of Class A Common Stock (in shares) | shares	1,290	1,526	1,344	1,530
Dilutive options, awards and common stock equivalents (in shares) | shares	478	240	506	241
Total weighted-average diluted Common Stock (in shares) | shares	18,562	18,864	18,712	19,038
Earnings Per Share [Abstract]
Basic earnings per share (in dollars per share) | $ / shares	$ 1.35	$ 0.98	$ 3.67	$ 1.80
Diluted earnings per share (in dollars per share) | $ / shares	$ 1.31	$ 0.97	$ 3.55	$ 1.77
Class A Common Stock [Member]
Earnings Per Share [Abstract]
Number of votes per share | Vote			10
Numerator [Abstract]
Distributed earnings	$ 297	$ 290	$ 868	$ 796
Undistributed earnings	1,348	1,140	3,774	1,825
Basic	$ 1,645	$ 1,430	$ 4,642	$ 2,621
Denominator [Abstract]
Weighted average shares outstanding (in shares) | shares	1,290	1,526	1,344	1,530
Earnings Per Share [Abstract]
Basic earnings per share (in dollars per share) | $ / shares	$ 1.28	$ 0.94	$ 3.45	$ 1.71
Diluted earnings per share (in dollars per share) | $ / shares	$ 1.25	$ 0.93	$ 3.38	$ 1.70