Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

The following table presents the unaudited consolidated operating results by quarter for the years ended December 31, 2017 and 2016:

	For the Three Months Ended
(in thousands, except per share data)	March 31,		June 30,		September 30,		December 31,^(a)
2017:
Revenues	$	300,129	$	356,185	$	373,502	$	373,501
Gross profit		25,740		27,517		34,853		36,894
Net income		1,200		1,230		5,145		13,579
Basic earnings per share	$	0.07	$	0.08	$	0.32	$	0.83
Diluted earnings per share	$	0.07	$	0.07	$	0.31	$	0.82
2016:
Revenues	$	253,634	$	261,934	$	283,259	$	343,660
Gross profit		27,281		31,435		34,063		41,944
Net income		1,987		5,500		6,146		7,798
Basic earnings per share	$	0.10	$	0.32	$	0.39	$	0.49
Diluted earnings per share	$	0.10	$	0.31	$	0.38	$	0.48

(a)

Results for the fourth quarter of 2017 include a net Tax Act benefit of $7.8 million, or $0.48 and $0.47 per basic and diluted share, respectively. See further discussion in Note 10 — Income Taxes to our Financial Statements.