Segment Information - Schedule of Segment Reporting Information (Details) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2022		Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021		Dec. 31, 2021
Segment Reporting Information [Line Items]
Net Sales		$ 266.2		$ 267.5		$ 477.2		$ 512.8
Income (Loss) from Operations		65.9		62.0		101.2		112.9
Assets		925.2	[1]	931.5	[1]	925.2	[1]	931.5	[1]	$ 883.3
Depreciation and Amortization		11.2		10.1		21.9		19.9
Capital Expenditures		14.9		9.7		24.8		17.7
Capital Markets - Software Solutions
Segment Reporting Information [Line Items]
Net Sales		46.3		43.8		91.0		82.3
Income (Loss) from Operations		3.1		9.3		7.4		15.8
Assets	[1]	196.8		178.0		196.8		178.0
Depreciation and Amortization		5.6		4.1		10.7		7.8
Capital Expenditures		7.5		4.5		12.8		8.2
Capital Markets - Compliance and Communications Management
Segment Reporting Information [Line Items]
Net Sales		150.0		153.1		253.6		291.6
Income (Loss) from Operations		60.5		64.6		89.4		123.7
Assets	[1]	475.9		466.2		475.9		466.2
Depreciation and Amortization		1.7		1.5		3.2		3.0
Capital Expenditures		2.0		0.7		2.7		1.3
Investment Companies - Software Solutions
Segment Reporting Information [Line Items]
Net Sales		25.3		22.8		50.4		44.6
Income (Loss) from Operations		5.9		3.5		12.1		5.5
Assets	[1]	97.3		92.3		97.3		92.3
Depreciation and Amortization		2.8		3.2		5.7		6.8
Capital Expenditures		4.2		2.7		7.2		4.5
Investment Companies - Compliance and Communications Management
Segment Reporting Information [Line Items]
Net Sales		44.6		47.8		82.2		94.3
Income (Loss) from Operations		13.7		2.1		21.8		8.4
Assets	[1]	58.3		68.9		58.3		68.9
Depreciation and Amortization		1.1		1.2		2.2		2.2
Capital Expenditures		0.7		0.8		1.3		1.3
Operating Segments
Segment Reporting Information [Line Items]
Net Sales		266.2		267.5		477.2		512.8
Income (Loss) from Operations		83.2		79.5		130.7		153.4
Assets	[1]	828.3		805.4		828.3		805.4
Depreciation and Amortization		11.2		10.0		21.8		19.8
Capital Expenditures		14.4		8.7		24.0		15.3
Corporate
Segment Reporting Information [Line Items]
Net Sales		0.0		0.0		0.0		0.0
Income (Loss) from Operations		(17.3)		(17.5)		29.5		(40.5)
Assets	[1]	96.9		126.1		96.9		126.1
Depreciation and Amortization		0.0		0.1		0.1		0.1
Capital Expenditures		$ 0.5		$ 1.0		$ 0.8		$ 2.4

[1] Certain assets are recorded within a segment based on predominant usage, however, as they benefit more than one segment, the related operating expenses are allocated between segments.