Restructuring and Reorganization Charges (Details Textual) $ in Thousands	3 Months Ended							12 Months Ended
	Dec. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) Employees	Dec. 31, 2015 USD ($) Employees	Dec. 31, 2014 USD ($) Employees	Dec. 31, 2013 USD ($)
Restructuring Cost And Reserve [Line Items]
Cash payments								$ 7,254	$ 6,129	$ 14,421
Reduced workforce | Employees								60	160	60
Restructuring and reorganization charges	$ 1,000	$ 5,300	$ (5,700)	$ 1,300	$ 800	$ 400	$ 600	$ 416	$ 3,074	$ 13,969
Asset impairment charge								194	1,685
Gain on disposition of business operations								6,611	3,733	222
Restructuring and reorganization reserve	3,746			2,994				3,746	2,994	3,948	$ 3,717
Current Liabilities
Restructuring Cost And Reserve [Line Items]
Restructuring and reorganization reserve	3,000							3,000
Cyber Security Business
Restructuring Cost And Reserve [Line Items]
Gain on disposition of business operations			$ 6,600						3,700
Termination costs
Restructuring Cost And Reserve [Line Items]
Cash payments										8,000
Termination Benefits
Restructuring Cost And Reserve [Line Items]
Cash payments								6,781	5,694	6,421
Restructuring and reorganization charges								7,201	4,544	5,589
Restructuring and reorganization reserve	2,414			1,637				2,414	1,637	2,819	$ 3,717
Facilities Abandonment
Restructuring Cost And Reserve [Line Items]
Cash payments								473	405
Restructuring and reorganization charges								556	1,175	1,146
Asset impairment charge								194
Restructuring and reorganization reserve	$ 1,332			$ 1,357				$ 1,332	$ 1,357	$ 1,113