Note 14 - Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	$ 30,383,000	$ 11,360,000
Effect of exchange rate changes on cash	(1,698,000)
Changes in cash and cash equivalents	(4,533,000)	(22,370,000)
Cash and cash equivalents	207,642,000	168,614,000
Additions to properties, plants, and equipment	(26,867,000)	(25,753,000)
Other investing activities, net	(2,485,000)	(2,448,000)
Dividends paid to stockholders	(995,000)	(138,000)
Payments on debt	(2,403,000)	(1,540,000)
Other financing activity	(468,000)	(3,851,000)
Consolidation, Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	(23,615,000)
Other investing activities, net	2,570,000
Other financing activity	21,045,000
Parent Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	31,570,000	(10,799,000)
Changes in cash and cash equivalents	10,981,000	(12,987,000)
Cash and cash equivalents	137,252,000
Additions to properties, plants, and equipment	(383,000)
Other investing activities, net	(2,570,000)	(140,000)
Dividends paid to stockholders	(995,000)	(138,000)
Borrowings on debt	(316,000)
Payments on debt	312,000
Other financing activity	(16,637,000)	(1,910,000)
Parent Company [Member] | Beginning Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	126,271,000	132,266,000
Parent Company [Member] | Ending Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	137,252,000	119,279,000
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	23,937,000	26,096,000
Changes in cash and cash equivalents	3,390,000	(9,014,000)
Cash and cash equivalents	43,399,000
Additions to properties, plants, and equipment	(13,628,000)	(25,753,000)
Other investing activities, net	(57,000)	250,000
Borrowings on debt	316,000
Payments on debt	(2,715,000)	(1,534,000)
Other financing activity	(4,463,000)	(8,073,000)
Guarantor Subsidiaries [Member] | Beginning Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	40,009,000	57,075,000
Guarantor Subsidiaries [Member] | Ending Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	43,399,000	48,061,000
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	(1,509,000)	(3,937,000)
Effect of exchange rate changes on cash	(1,698,000)
Changes in cash and cash equivalents	(18,904,000)	(369,000)
Cash and cash equivalents	26,991,000
Additions to properties, plants, and equipment	(12,856,000)
Other investing activities, net	(2,428,000)	(2,558,000)
Payments on debt		(6,000)
Other financing activity	(413,000)	6,132,000
Non-Guarantor Subsidiaries [Member] | Beginning Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	45,895,000	1,643,000
Non-Guarantor Subsidiaries [Member] | Ending Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	26,991,000	1,274,000
Beginning Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	212,175,000	190,984,000
Ending Balance [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	$ 207,642,000	$ 168,614,000