Note 4 - Financing Arrangements (Detail) - Outstanding Borrowings (USD $)	Mar. 31, 2013	Dec. 31, 2012
Less current portion of long-term debt	$ (200,000,000)	$ (100,000,000)
Total long-term debt	393,289,000	585,347,000
Line of Credit [Member] | Senior Debt Obligations [Member]
Senior revolving line of credit	43,700,000	85,800,000
Loans Payable [Member] | Senior Debt Obligations [Member]
Long-term debt	150,000,000	200,000,000
Senior Notes [Member] | Senior Debt Obligations [Member]
Long-term debt	$ 399,600,000	$ 399,500,000