Deficit (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Changes in shareholders equity that are attributable to shareholders and noncontrolling interests
Balance	$ (44,378)	$ (59,485)
Net (loss) income	4,740	(1,890)
Other comprehensive income	210	179
Share-based compensation	746	758
Stock option exercised	277	22
Cash distributions to noncontrolling interests	(120)	(77)
Balance	(32,304)	(60,493)
Additional Paid-in Capital
Changes in shareholders equity that are attributable to shareholders and noncontrolling interests
Balance	250,018	244,986
Share-based compensation	746	758
Stock option exercised	277	22
Balance	251,041	245,766
Accumulated Deficit
Changes in shareholders equity that are attributable to shareholders and noncontrolling interests
Balance	(287,998)	(296,826)
Net (loss) income	4,654	(1,963)
Balance	(277,123)	(298,789)
Accumulated Other Comprehensive Loss
Changes in shareholders equity that are attributable to shareholders and noncontrolling interests
Balance	(6,638)	(7,826)
Other comprehensive income	210	179
Balance	(6,428)	(7,647)
Noncontrolling Interests
Changes in shareholders equity that are attributable to shareholders and noncontrolling interests
Balance	240	181
Net (loss) income	86	73
Cash distributions to noncontrolling interests	(120)	(77)
Balance	206	$ 177
Accounting Standards Update 2014-09
Changes in shareholders equity that are attributable to shareholders and noncontrolling interests
Impact of change in accounting policy	6,221
Accounting Standards Update 2014-09 | Accumulated Deficit
Changes in shareholders equity that are attributable to shareholders and noncontrolling interests
Impact of change in accounting policy	$ 6,221