Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue, Net	$ 182,586	$ 171,128	$ 178,073	$ 122,633	$ 131,433	$ 127,202	$ 120,921	$ 107,561
Income (Loss) from Continuing Operations before Interest Expense, Interest Income, Income Taxes, Noncontrolling Interests, Net	27,809	(45,487)	12,650	5,938	(17,578)	5,041	15,210	4,330
Net Income (Loss) Attributable to Parent	$ 27,001	$ (28,012)	$ 7,257	$ 3,899	$ (10,517)	$ 3,423	$ 9,841	$ 2,951	$ 10,145	$ 5,698	$ 27,358
Earnings Per Share, Basic	$ 0.63	$ (0.66)	$ 0.17	$ 0.18	$ (0.49)	$ 0.16	$ 0.46	$ 0.14	$ 0.27	$ 0.27	$ 1.29
Earnings Per Share, Diluted	$ 0.63	$ (0.66)	$ 0.17	$ 0.18	$ (0.49)	$ 0.16	$ 0.45	$ 0.14	$ 0.27	$ 0.26	$ 1.28