Note 9 - Stockholders' Equity and Equity Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

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

	Six Months Ended June 30, 2019
	Stock Awards			Weighted Average Award Date Fair Value
Outstanding at December 31, 2018		1,143,205		$	23.26
Restricted stock units awarded		297,865			20.10
Performance stock units awarded		146,367			22.78
Restricted stock units distributed		(205,274	)		18.49
Performance stock units distributed		(111,155	)		25.85
Restricted stock units forfeited		(20,871	)		23.35
Performance stock units forfeited		(44,567	)		25.98
Outstanding at June 30, 2019		1,205,570		$	22.89

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

	Six Months Ended June 30, 2019
	Deferred Stock Units			Weighted Average Award Date Fair Value
Outstanding at December 31, 2018		287,350		$	20.80
Awarded		45,047			19.67
Distributed		(77,486	)		20.39
Outstanding at June 30, 2019		254,911		$	20.73