Significant Accounting Policies - (Details 5) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) facility	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Property, Plant and Equipment [Line Items]
Number of facilities which provide services (more than 30) | facility									30
Revenues	$ 129,815	$ 121,968	$ 122,345	$ 121,173	$ 146,518	$ 134,121	$ 140,310	$ 132,727	$ 495,301	$ 553,676	$ 559,609
Property, plant and equipment	33,913				36,913				33,913	36,913
UNITED STATES
Property, Plant and Equipment [Line Items]
Revenues									411,775	463,752	469,596
Property, plant and equipment	29,437				33,134				$ 29,437	33,134
Foreign Countries
Property, Plant and Equipment [Line Items]
Number of facilities which provide services (more than 30) | facility									6
Revenues									$ 83,526	89,924	$ 90,013
Property, plant and equipment	4,476				3,779				4,476	3,779
Other Current Assets | New Accounting Pronouncement, Early Adoption, Effect
Property, Plant and Equipment [Line Items]
Deferred tax asset	$ (3,700)				$ (5,100)				$ (3,700)	$ (5,100)