Note 8 - Employee Benefit Plans (Detail) - Change In Benefit Obligation (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	$ 87,895	$ 76,925
Service cost	3,974	3,877
Interest cost	4,069	4,114
Participants' contributions	29
Amendments		396
Actuarial loss	7,450	6,476
Benefits paid	(4,050)	(3,893)
Benefit obligation at end of year	99,367	87,895
Change in fair value of plan assets:
Fair value of plan assets at beginning of year	65,082	70,462
Actual return (loss) on plan assets	6,007	1,818
Employer contributions	1,447	331
Participants' contributions	29
Benefits paid	(4,050)	(3,893)
Fair value of plan assets at end of year	68,515	65,082
Funded status at end of year	(30,852)	(22,813)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	65	68
Interest cost	3	3
Actuarial loss	7	4
Benefits paid	(12)	(10)
Benefit obligation at end of year	63	65
Change in fair value of plan assets:
Employer contributions	12	10
Benefits paid	(12)	(10)
Funded status at end of year	$ (63)	$ (65)