Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Stock-Based Compensation [Abstract]

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

The following table summarizes our restricted stock award activity for the years ended December 31, 2018, 2017 and 2016. The vesting dates for the awards vested in 2018 occurred relatively evenly throughout the year ended December 31, 2018. The fair value of awards vested during 2018, 2017 and 2016 was $0.8 million, $0.6 million and $2.0 million, respectively.

	2018
	Number of Restricted Stock Awards (in thousands)	Weighted Average Grant Date Fair Value
Unvested at January 1	53.7	$	21.82
Granted	10.0	18.58
Vested	(35.7)	21.48
Forfeited	(1.5)	17.11
Outstanding (unvested) at end of year	26.5	$	21.31

	2017
	Number of Restricted Stock Awards (in thousands)	Weighted Average Grant Date Fair Value
Unvested at January 1	53.0	$	21.53
Granted	27.0	22.98
Vested	(25.3)	22.07
Forfeited	(1.0)	17.11
Outstanding (unvested) at end of year	53.7	$	21.82

	2016
	Number of Restricted Stock Awards (in thousands)	Weighted Average Grant Date Fair Value
Unvested at beginning of year	102.4	$	18.36
Granted	74.0	17.27
Vested	(122.2)	16.21
Forfeited	(1.2)	22.21
Outstanding (unvested) at end of year	53.0	$	21.53