Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 04, 2015	Sep. 28, 2014	Oct. 04, 2015	Sep. 28, 2014	Dec. 31, 2014
Assets and Liabilities
Held for sale assets	$ 0		$ 0		$ 29,814
Held for sale liabilities	0		0		12,191
Revenue and Expenses
Pretax income from discontinued operations	0	$ 2,719	1,228	$ 6,683
Discontinued operations, net of tax	78,290	2,719	79,518	6,683
Significant Noncash Items
Capital expenditures			482	467
SISD | Discontinued Operations, Disposed of by Sale
Assets and Liabilities
Accounts receivable, net					10,885
Inventories, net					6,313
Unbilled revenue					2,356
Prepaid expenses and other current assets					2,955
Property, plant, and equipment, net					1,944
Intangible assets, net					1,029
Goodwill					4,301
Other assets					31
Held for sale assets					29,814
Accounts payable					1,891
Accrued expenses					4,335
Deferred revenue					5,965
Held for sale liabilities					$ 12,191
Revenue and Expenses
Revenue	0	15,000	23,248	41,139
Cost of revenue	0	(6,514)	(11,291)	(18,462)
Research, development, and engineering expenses	0	(1,033)	(2,126)	(3,101)
Selling, general, and administrative expenses	0	(3,364)	(7,800)	(9,748)
Foreign currency gain (loss)	0	(78)	(177)	(100)
Pretax income from discontinued operations	0	4,011	1,854	9,728
Gain on Disposal of Discontinued Operation, pretax	125,465	0	125,465	0
Income from discontinued operations, total pretax	125,465	4,011	127,319	9,728
Income tax expense	47,175	1,292	47,801	3,045
Discontinued operations, net of tax	78,290	2,719	79,518	6,683
Significant Noncash Items
Stock-based compensation expense	1,106	231	1,533	786
Depreciation expense	0	196	401	584
Amortization expense	0	94	165	282
Capital expenditures	$ 0	$ 206	$ 482	$ 467