Segment and Related Information - Revenue by Major Customers (Details) - Customer Concentration Risk - Revenue	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue, Major Customer [Line Items]
Percentage of revenue generated by customer	100.00%	100.00%	100.00%
Reportable Segments | Restaurant/Retail | Dairy Queen
Revenue, Major Customer [Line Items]
Percentage of revenue generated by customer	13.00%	9.00%	3.00%
Reportable Segments | Restaurant/Retail | Yum! Brands, Inc.
Revenue, Major Customer [Line Items]
Percentage of revenue generated by customer	11.00%	16.00%	13.00%
Reportable Segments | Restaurant/Retail | McDonald’s Corporation
Revenue, Major Customer [Line Items]
Percentage of revenue generated by customer	7.00%	10.00%	19.00%
Reportable Segments | Government | U.S. Department of Defense
Revenue, Major Customer [Line Items]
Percentage of revenue generated by customer	33.00%	34.00%	33.00%
All Others
Revenue, Major Customer [Line Items]
Percentage of revenue generated by customer	36.00%	31.00%	32.00%