Note 8 - Income Taxes - Significant Components of Deferred Tax Liabilities and Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax liabilities:
Net book value of property and equipment	$ 21,097	$ 18,131
Broadcast licenses, goodwill and other intangibles	286,299	272,330
Total deferred tax liabilities	307,396	290,461
Deferred tax assets:
Liability for accrued vacation	1,461	1,438
Liability for accrued bonus	3,993	2,391
Allowance for doubtful accounts	1,358	1,170
Liability under health and welfare plan	639	608
Liability for pension plan	8,437	9,611
State and local operating loss carryforwards	2,358	4,719
Alternative minimum tax carryforwards		3,925
Acquisition costs	1,946	2,104
Restricted stock	2,083	2,636
Other	231	244
Total deferred tax assets	22,506	28,846
Valuation allowance for deferred tax assets		(75)
Net deferred tax assets	22,506	28,771
Deferred tax liabilities, net of deferred tax assets	$ 284,890	$ 261,690