Note 11 - Share Based Compensation and Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Share-based Payment Arrangement, Option, Activity [Table Text Block]

						Weighted
				Weighted		Average
				Average		Remaining		Aggregate
				Exercise		Contractual		Intrinsic
Options	Shares			Price		Life (in Years)		Value
Balance of Outstanding Options at January 1, 2019		2,984,280		$	27.63
Granted		482,663			41.15
Exercised		(375,950	)		20.19
Forfeited		(23,333	)		33.84
Balance of Outstanding Options at December 31, 2019		3,067,660		$	30.62		5.96	$	48,712,030
Expected to vest after December 31, 2019		1,778,219		$	34.70		7.64	$	20,984,383
Vested and exercisable at December 31, 2019		1,259,505		$	24.65		3.55	$	27,521,030

Schedule of Nonvested Share Activity [Table Text Block]

				Weighted
				Average
	Number of			Grant Date
Non-vested Shares	Shares			Fair Value
Non-vested at January 1, 2019		1,796,356		$	11.74
Granted		482,663			12.56
Vested		(447,531	)		11.12
Forfeited		(23,333	)		11.92
Non-vested at December 31, 2019		1,808,155		$	12.11

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

				Weighted
				Average				Weighted
				Remaining		Aggregate		Average
				Contractual		Intrinsic		Grant Date
Stock Awards and Units	Shares			Life (in Years)		Value		Fair Value
Outstanding non-vested shares at January 1, 2019		573,134						$	34.07
Granted		330,909							40.36
Vested		(293,615	)						30.32
Outstanding non-vested at December 31, 2019		610,428			8.6	$	27,896,560	$	39.06
Expected to vest after December 31, 2019		609,419			8.6	$	27,850,441