Share-Based Compensation And Share Repurchase Plans (Tables)

12 Months Ended

Dec. 31, 2019

Share-Based Compensation And Share Repurchase Plans [Abstract]

Schedule Of Fair Value Of Options, Weighted Average Assumptions

	2019		2018		2017
Stock option exercise price	$	16.12	$	16.40	$	15.94
Risk-free interest rate		2.42%		2.56%		1.66%
Expected dividend yield		—		—		—
Expected option life in years		3.75		3.75		3.75
Expected volatility		23.32%		24.99%		24.95%
Weighted average fair value	$	3.50	$	3.80	$	3.45

Schedule Of Stock Options Outstanding And Exercisable

	Outstanding Stock Options
	Number of Options		Weighted Average Exercise Price				Weighted Average Remaining Years of Contractual Life	Aggregate Intrinsic Value
	Class A	Class B	Class A		Class B		Class A&B	Class A&B
Outstanding - January 1, 2017	535,077	—	$	9.84	$	—	2.61	$	3,615,191
Granted	169,762	—		15.94		—
Exercised	(177,750)	—		7.85		—			702,840
Expired	(2,500)	—		6.23		—
Outstanding - December 31, 2017	524,589	—	$	12.50	$	—	3.15	$	3,054,325
Granted	126,840	—		16.40		—
Exercised	(60,000)	—		6.02		—			610,249
Expired	(4,960)	—		12.08		—
Outstanding - December 31, 2018	586,469	—	$	14.01	$	—	2.88	$	1,530,528
Granted	219,408	—		16.12		—
Exercised	(69,500)	—		13.42		—			185,175
Expired	(25,000)	—		13.42		—
Outstanding - December 31, 2019	711,377	—	$	14.74	$	—	2.79	$	136,350

Summary Of Vested And Unvested Stock Options

	Vested and Unvested Stock Options
	Number of Options		Weighted Average Exercise Price				Weighted Average Remaining Years of Contractual Life	Aggregate Intrinsic Value
	Class A	Class B	Class A			Class B	Class A&B	Class A&B
Vested
December 31, 2019	273,866	—	$	12.59	$	—	1.87	$	136,350
December 31, 2018	231,124	—		12.38		—	2.28		1,306,643
December 31, 2017	186,832	—		9.84		—	2.30		2,202,772
Unvested
December 31, 2019	437,511	—	$	15.78	$	—	3.36	$	—
December 31, 2018	355,345	—		15.07		—	3.27		223,885
December 31, 2017	337,757	—		13.86		—	3.62		851,552

Schedule Of Restricted Stock Units Issued And Vested

	Number of RSUs					$ value of RSUs
	Granted	Vesting	Forfeited	Unvested	Granted		Vesting			Forfeited	Unvested
2016	68,153	59,646	517	7,990	$	810,779	$	708,904	$	6,245	$	95,629
2017	70,538	52,465	—	18,073		1,124,348		836,258		—		288,090
2018	97,600	63,480	932	33,188		1,581,512		1,021,776		15,005		544,731
2019	59,258	—	—	59,258		944,070		—		—		944,070
Total	295,549	175,591	1,449	118,509	$	4,460,709	$	2,566,938	$	21,250	$	1,872,520