Note 5 - Financing Arrangements and Fair Value of Financial Instruments (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Debt Instrument, Face Amount	$ 172,500,000
Line of Credit Facility, Increase, Additional Borrowings	75,000,000
Line of Credit Facility, Amount Outstanding	70,000,000
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	197,500,000	176,000,000
Minimum [Member]
Line of Credit Facility, Maximum Borrowing Capacity	125,000,000
Maximum [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 200,000,000