Quarterly Historical Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2018

Selected Quarterly Financial Information [Abstract]

Schedule of Quarterly Financial Information

The following table sets forth selected unaudited historical operating results data for each quarter (in thousands):

	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
2018
Revenues	$	73,815	$	70,676	$	78,067	$	75,522
Operating income	$	20,364	$	19,495	$	21,428	$	17,048
Net income	$	11,760	$	11,125	$	13,317	$	9,443
2017
Revenues	$	73,794	$	66,053	$	73,938	$	74,648
Operating income	$	23,376	$	17,712	$	23,698	$	19,040
Net income	$	12,570	$	9,287	$	13,826	$	15,615