Note 9 - Retirement Plans (Detail) - Target asset allocation	12 Months Ended
	Dec. 31, 2012
Large Cap Equities [Member]
Asset class:
Target Plan Asset Allocations Range Minimum	23.00%
Target Plan Asset Allocations Range Maximum	91.00%
Mid Cap Equities [Member]
Asset class:
Target Plan Asset Allocations Range Minimum	0.00%
Target Plan Asset Allocations Range Maximum	15.00%
Small Cap Equities [Member]
Asset class:
Target Plan Asset Allocations Range Minimum	0.00%
Target Plan Asset Allocations Range Maximum	16.00%
International Equities [Member]
Asset class:
Target Plan Asset Allocations Range Minimum	5.00%
Target Plan Asset Allocations Range Maximum	25.00%
Fixed Income Securities [Member]
Asset class:
Target Plan Asset Allocations Range Minimum	0.00%
Target Plan Asset Allocations Range Maximum	30.00%
Cash [Member]
Asset class:
Target Plan Asset Allocations Range Minimum	0.00%
Target Plan Asset Allocations Range Maximum	20.00%