Note 9 - Retirement Plans (Detail) (USD $)	12 Months Ended								0 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2012 Active Defined Benefit Pension Plan [Member]	Dec. 31, 2011 Active Defined Benefit Pension Plan [Member]	Dec. 31, 2010 Active Defined Benefit Pension Plan [Member]	Dec. 31, 2012 Acquired Pension Plans [Member]	Dec. 31, 2011 Acquired Pension Plans [Member]	Dec. 09, 2008 Capital Accumulation Plan [Member]	May 02, 2007 Capital Accumulation Plan [Member]	Dec. 31, 2012 Capital Accumulation Plan [Member]	Dec. 31, 2012 Collective Bargaining [Member]
Defined Benefit Plan, Accumulated Benefit Obligation				$ 71,800,000	$ 58,100,000
Defined Benefit Plan, Current Assets							4,900,000	4,400,000
Defined Benefit Plan, Benefit Obligation				83,236,000	67,033,000	50,055,000	7,400,000	6,800,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year		$ 3,100,000	$ 8,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in Shares)									2,000,000	1,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)											1,600,988
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent	6.00%											50.00%