Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information [Table Text Block]

2019:	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Operating revenues	$	415,363	$	413,862	$	428,503	$	449,633
Operating income		12,638		8,787		3,282		1,363
Net income (loss)(1)		4,721		2,672		(1,446)		(9,594)
Basic earnings (loss) per share		0.10		0.05		(0.03)		(0.20)
Diluted earnings (loss) per share		0.10		0.05		(0.03)		(0.20)

2018:	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Operating revenues	$	425,708	$	449,758	$	460,227	$	469,222
Operating income(2)		14,854		20,018		22,892		21,142
Net income (2)(3)		1,159		615		16,129		6,996
Basic earnings  per share		0.18		0.04		0.33		0.14
Diluted earnings per share		0.18		0.04		0.33		0.14

(1)Fourth quarter 2019 results include an impairment charge of $6.8 million related to our Arnold note receivable.

(2)Fourth quarter 2018 results include an impairment charge of $10.7 million related to assets of business held for sale

(3)Fourth quarter 2018 results include an impairment charge of $1.8 million related to equity method investments