Equity Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2017

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

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

Restricted share activity is summarized as follows (in thousands, except per share data):

	Shares Outstanding		Weighted Average Grant Date Fair Value
Unvested restricted stock at December 31, 2014		239	$	26.24
Restricted stock granted		86	$	33.46
Restricted stock vested		(80)	$	25.13
Restricted stock forfeited		(32)	$	29.54
Unvested restricted stock at December 31, 2015		213	$	29.07
Restricted stock granted		93	$	37.67
Restricted stock vested		(72)	$	27.07
Restricted stock forfeited		(6)	$	35.58
Unvested restricted stock at December 31, 2016		228	$	33.02
Restricted stock granted		88	$	48.59
Restricted stock vested		(78)	$	30.95
Restricted stock forfeited		(11)	$	39.68
Unvested restricted stock at December 31, 2017		227	$	39.47