Note 15 - Retirement Benefit Plans (Detail) - Obligation and Funded Status (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Benefit obligation at beginning of year	$ 3,117	$ 3,178	$ 3,519
Service cost	(340)	(35)	(371)
Interest cost	143	175	193
Benefits paid	(165)	(201)	(163)
Benefit obligation at end of year	2,755	3,117	3,178
Accumulated post-retirement benefit obligation attributable to:
Benefit obligation at end of year	2,755	3,117	3,178
Accumulated post-retirement benefit obligation in excess of plan assets	2,755	3,117	3,178
Retirees [Member]
Benefit obligation at end of year	1,654	2,363	1,990
Accumulated post-retirement benefit obligation attributable to:
Benefit obligation at end of year	1,654	2,363	1,990
Fully Eligible Participants [Member]
Benefit obligation at end of year	856	537	951
Accumulated post-retirement benefit obligation attributable to:
Benefit obligation at end of year	856	537	951
Other Participants [Member]
Benefit obligation at end of year	245	217	237
Accumulated post-retirement benefit obligation attributable to:
Benefit obligation at end of year	$ 245	$ 217	$ 237