Note 8 - Employee Benefit Plans (Detail) - Net Periodic Pension Cost (Income) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Benefits [Member]
Service cost	$ 3,974	$ 3,877	$ 2,203
Interest cost	4,068	4,114	3,724
Expected return on plan assets	(4,581)	(5,481)	(5,041)
Amortization of prior service cost	401	403	602
Amortization of net gain (loss) from earlier periods	2,826	880	867
Net periodic pension cost	6,688	3,793	2,355
Other Benefits [Member]
Interest cost	3	4	4
Amortization of net gain (loss) from earlier periods	(28)	(31)	(33)
Net periodic pension cost	$ (25)	$ (27)	$ (29)