Note 9 - Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

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

	RSU Awards					PRSU Awards
				Weighted-Average					Weighted-Average
				Grant-Date					Grant-Date
	Shares			Fair Value		Shares			Fair Value
Non-vested at December 31, 2018		502,658		$	24.93		-		$	-
Granted		263,574			22.38		57,870			22.38
Vested		(259,329	)		23.24		(27,110	)		22.38
Forfeited		(21,545	)		24.81		-			-
Non-vested at June 30, 2019		485,358		$	24.45		30,760		$	22.38
Vested but unissued at June 30, 2019		218,778		$	24.64		21,310		$	22.38

Phantom Share Units (PSUs) [Member]

Notes Tables

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

Phantom Stock Plan	Shares			Fair Value
Outstanding at December 31, 2018		99,313		$	21.53
Granted		9,175			22.15
Distributions		(1,012	)		22.00
Outstanding at June 30, 2019		107,476		$	22.20
Vested at June 30, 2019		106,929		$	22.20