Segment and Related Information, Revenue by Major Customers (Details)	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Revenue, Major Customer [Line Items]
Concentration risk, percentage	100.00%	100.00%
Operating segments \| Restaurant/Retail \| McDonald’s Corporation
Revenue, Major Customer [Line Items]
Concentration risk, percentage	27.00%	44.00%
Operating segments \| Restaurant/Retail \| Yum! Brands, Inc.
Revenue, Major Customer [Line Items]
Concentration risk, percentage	11.00%	12.00%
Operating segments \| Government \| U.S. Department of Defense
Revenue, Major Customer [Line Items]
Concentration risk, percentage	29.00%	22.00%
Other
Revenue, Major Customer [Line Items]
Concentration risk, percentage	33.00%	22.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration