Note 7 - Financing Arrangements and Fair Value of Financial Instruments (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Senior Notes [Member]
Note 7 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Debt Instrument, Face Amount	$ 172,500,000
Debt Instrument, Interest Rate, Stated Percentage	4.00%
Debt Conversion Converted Instrument Shares Issued For Basis Principal (in Shares)	90.8893
Debt Conversion Principal Amount Of Senior Notes As Basis For Conversion Rate	1,000
Debt Instrument, Convertible, Conversion Price (in Dollars per share)	$ 11.00
Fair Value, Estimate Not Practicable, Senior Debt Obligations	234,600,000	176,000,000
Revolving Credit Facility [Member]
Note 7 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Additional Borrowing Capacity on Credit Facility	75,000,000
Line of Credit Facility, Amount Outstanding	47,000,000
Minimum [Member] | Revolving Credit Facility [Member]
Note 7 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	125,000,000
Maximum [Member] | Revolving Credit Facility [Member]
Note 7 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 200,000,000