Acquisitions - Narrative (Details) - USD ($)			1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Aug. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired						$ 169,200,000	$ 0
Acquisition-related and integration charges				$ 2,700,000	$ 200,000	$ 10,300,000	3,700,000
Cummins-Allison
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue					$ 821,900,000		$ 2,590,900,000
Payments to Acquire Businesses, Gross		$ 160,000,000
Payments to Acquire Businesses, Net of Cash Acquired		156,200,000
Debt instrument, face amount		$ 150,000,000						$ 150,000,000
I&S (acquisition)
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 172,300,000		$ 169,200,000
Debt instrument, face amount	100,000,000
Proceeds from Lines of Credit	$ 67,000,000
Working Capital Adjustment			$ 3,100,000
Trade Names | Cummins-Allison
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Remaining Amortization Period						7 years
Trade Names | I&S (acquisition)
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Remaining Amortization Period						13 years
Customer Relationships | Cummins-Allison
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Remaining Amortization Period						18 years
Customer Relationships | I&S (acquisition)
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Remaining Amortization Period								14 years
Technology-Based Intangible Assets | Cummins-Allison
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Remaining Amortization Period						10 years