Divestiture and Discontinued Operations - Narrative (Details) - PAR Springer Miller Systems Inc - USD ($)	May 05, 2017	Nov. 04, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total consideration		$ 16,600,000
Consideration received	$ 4,200,000	12,100,000
Consideration receivable		4,500,000
Contingent consideration receivable upon achievement of targets		1,500,000.0
Contingent consideration receivable upon achievement of targets, maximum per calendar year		$ 500,000