Note 8 - Revolving Lines Of Credit And Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Debt Instrument, Basis Spread on Variable Rate	0.25%
Canada [Member]
Line of Credit Facility, Remaining Borrowing Capacity (in Dollars)	5
United States [Member]
Line of Credit Facility, Remaining Borrowing Capacity (in Dollars)	30
Canada [Member]
Debt Instrument, Basis Spread on Variable Rate	2.00%
Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate	2.15%
Standby Letters of Credit [Member]
Letters of Credit Outstanding, Amount (in Dollars)	0.3