Commitments And Contingencies (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 30, 2016	Dec. 31, 2018
Tax Audit/Litigation [Member]
Commitments And Contingencies [Line Items]
Income tax obligation		$ 3,000,000
Cotter, Jr. Related Litigation Matters [Member]
Commitments And Contingencies [Line Items]
Settlement awarded		1,550,000
Settlement awarded to the other party		443,000
Arbitration reimbursement from other party		19,250
Separation payment amount		$ 313,000
Separation payment interest percent		10.00%
Full amount of separation payment amount		$ 86,000
Damages sought		787,769
Legal fees		5,900,000
Litigation expense		3,500,000
Coverage limit		$ 10,000,000
The STOMP Arbitration [Member]
Commitments And Contingencies [Line Items]
Settlement awarded	$ 2,300,000
Class B [Member] | Cotter Estate [Member] | Cotter, Jr. Related Litigation Matters [Member]
Commitments And Contingencies [Line Items]
Shares held by estate		427,808
Voting stock percent		25.50%
Class B [Member] | Cotter Trust [Member] | Cotter, Jr. Related Litigation Matters [Member]
Commitments And Contingencies [Line Items]
Shares held by estate		696,080
Voting stock percent		41.40%
Class B [Member] | Cotter Voting Trust [Member] | Cotter, Jr. Related Litigation Matters [Member]
Commitments And Contingencies [Line Items]
Shares held by estate		1,123,888
Voting stock percent		66.90%