Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 181,089	$ 187,652	$ 183,148	$ 180,127	$ 182,586	$ 171,128	$ 178,073	$ 122,633	$ 723,942	$ 654,420	$ 487,117
Income (Loss) from Continuing Operations before Interest Expense, Interest Income, Income Taxes, Noncontrolling Interests, Net	(19,416)	(15,870)	19,332	11,716	27,809	(45,487)	12,650	5,938
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(10,968)	(11,707)	14,701	8,369	27,001	(28,012)	7,257	3,899	394	10,145	5,698
Net Income (Loss) Attributable to Noncontrolling Interest	103	1	0	0	0	0	0	0	104	0	0
Net Income (Loss) Attributable to Parent	$ (11,071)	$ (11,708)	$ 14,701	$ 8,369	$ 27,001	$ (28,012)	$ 7,257	$ 3,899	$ 290	$ 10,145	$ 5,698
Earnings Per Share, Basic	$ (0.26)	$ (0.27)	$ 0.34	$ 0.20	$ 0.63	$ (0.66)	$ 0.17	$ 0.18	$ 0.01	$ 0.27	$ 0.27
Earnings Per Share, Diluted	$ (0.26)	$ (0.27)	$ 0.34	$ 0.20	$ 0.63	$ (0.66)	$ 0.17	$ 0.18	$ 0.01	$ 0.27	$ 0.26