Restructuring (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 3,071,000	$ 317,000	$ 4,713,000	$ 8,316,000
March 2015 Plan and September 2015 Reduction
Restructuring Cost and Reserve [Line Items]
Restructuring charges			(800,000)
March 2015 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	300,000	(100,000)	6,300,000
Restructuring and related cost, cost incurred to date	20,500,000		20,500,000
September 2015 Reduction
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	$ 0	(700,000)	$ 2,000,000
Restructuring and related cost, cost incurred to date	7,200,000		7,200,000
June 2017 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3,100,000
Restructuring and related cost, cost incurred to date	5,500,000		5,500,000
Minimum | June 2017 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	8,000,000		8,000,000
Maximum | June 2017 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	$ 19,000,000		$ 19,000,000
Disposed of by Sale | Hyderabad
Restructuring Cost and Reserve [Line Items]
Ownership percentage	100.00%		100.00%