Note 5 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

(In thousands)	2014		2013		2012
Current:
Federal	$	10,402	$	15,964	$	12,728
State		2,015		1,889		587
		12,417		17,853		13,315
Deferred:
Federal		8,648		3,909		5,542
State		774		394		(720	)
		9,422		4,303		4,822
Total provision	$	21,839	$	22,156	$	18,137

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	2014			2013			2012
Statutory federal income tax rate		35	%		35	%		35	%
Per diem and other non-deductible expenses		4			4			5
Increase in taxes arising from state income taxes, net of federal income tax benefit		3			3			-
Effective tax rate		42	%		42	%		40	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

(In thousands)	2014		2013
Deferred tax assets:
Reserves and accrued liabilities	$	6,049	$	6,051
Other		2,847		2,796
		8,896		8,847
Deferred tax liabilities:
Depreciation		125,697		116,438
Prepaid expenses		2,843		2,631
		128,540		119,069
Net deferred tax liability	$	119,644	$	110,222