Summary of Significant Accounting Policies Sabbatical Leave (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Jan. 02, 2016
Compensated Absences Liability, Sabbatical Leave	$ 1,000	$ 1,200
Minimum [Member]
sabbatical minimum service time	5 years

Amount of liability accrued for the employer's obligation related to an employee's right to receive compensation during a future sabbatical leave. This amount does not include amounts accrued for the employee's future vacation and holidays.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Sabbatical Leave
-URI http://asc.fasb.org/extlink&oid=6524516

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6409733&loc=d3e19366-108361

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 25
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6409733&loc=d3e19437-108361

Name:	us-gaap_CompensatedAbsencesLiabilitySabbaticalLeave
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant