Note 14 - Stock Incentive and Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Compensation, Stock Options and Stock Appreciation Rights Award Activity [Table Text Block]

	2015					2014					2013
	Number of Shares			Weighted Average Exercise Price		Number of Shares			Weighted Average Exercise Price		Number of Shares			Weighted Average Exercise Price
Outstanding, beginning of year		4,418,308		$	29.19		3,956,373		$	27.70		3,723,276		$	21.05
Granted		2,167,150			34.32		1,303,054			39.50		1,252,320			42.00
Exercised		(1,287,216	)		14.17		(524,185	)		18.20		(895,865	)		17.75
Canceled		(397,625	)		48.61		(316,934	)		71.20		(123,359	)		43.95
Outstanding, end of year		4,900,617		$	33.83		4,418,308		$	29.19		3,956,373		$	27.70
Exercisable at end of year		2,554,114		$	28.90		1,952,477		$	19.90		1,947,313		$	21.40
Available for future grant		9,061,407					10,246,013					2,794,218

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

Outstanding										Exercisable
Exercise Prices				Number		Weighted Average Exercise		Weighted Average Remaining Contractual		Number		Weighted Average Exercise
Low		High		of Shares		Price		Life		of Shares		Price
$	3.35	$	21.45		1,680,292	$	19.52		1.69		1,406,292	$	19.52
$	28.35	$	41.16		1,212,111	$	38.83		3.99		280,230	$	38.83
$	41.95	$	46.45		2,008,214	$	42.77		2.89		867,592	$	42.77

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2015			2014			2013
Dividend yield		0.00	%		0.00	%		0.00	%
Expected volatility		40.89	%		48.44	%		57.70	%
Risk-free interest rate		0.93	%		0.95	%		0.36	%
Expected life (years)		3.5			3.5			3.5

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	2015					2014					2013
	Number of Shares			Weighted Average Grant Date		Number of Shares			Weighted Average Grant Date		Number of Shares			Weighted Average Grant Date
Outstanding, beginning of year		154,143		$	37.55		107,706		$	33.60		68,890		$	21.55
Granted		133,616			41.89		94,590			39.20		63,529			41.95
Vested		(82,293	)		35.75		(42,310	)		31.60		(22,964	)		21.55
Canceled		(10,439	)		41.26		(5,843	)		33.65		(1,748	)		21.45
Outstanding, end of year		195,027		$	41.08		154,143		$	37.55		107,706		$	33.60

Schedule of Nonvested Performance-based Units Activity [Table Text Block]

	2015					2014				2013
	Number of Shares			Weighted Average Grant Date		Number of Shares		Weighted Average Grant Date		Number of Shares			Weighted Average Grant Date
Outstanding, beginning of year		166,031		$	36.20		120,448	$	29.05		81,002		$	21.45
Granted		348,756			30.46		45,583		55.05		44,691			41.95
Vested		(316,028	)		22.68		—		—		—			—
Canceled					—		—		—		(5,245	)		21.45
Outstanding, end of year		198,759		$	47.63		166,031	$	36.20		120,448		$	29.05

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

	Year Ended December 31,
	2015		2014		2013
	(Dollars in thousands)
Stock options and stock appreciation rights	$	8,709	$	3,618	$	3,875
Unrestricted stock grants		555		480		400
Restricted stock grants		3,261		1,842		1,073
Performance share awards		3,099		2,529		3,667
Total	$	15,624	$	8,469	$	9,015

Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block]

	As of December 31,
	2015				2014				2013
	Unrecognized Expense		Weighted Average Period (years)		Unrecognized Expense		Weighted Average Period (years)		Unrecognized Expense		Weighted Average Period (years)
	(Dollars in thousands)
Unvested stock options and stock appreciation rights	$	7,216		2.1	$	6,777		2.1	$	5,260		1.9
Unvested restricted stock grants		5,850		2.1		4,090		2.1		2,473		2.0
Unvested performance share awards		5,117		2.0		3,267		1.7		7,320		1.8
Total unrecognized compensation expense	$	18,183		2.0	$	14,134		2.0	$	15,053		1.9