Significant Accounting Policies and Practices - Sale of Business (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration received		$ 0.0	$ 1.0
Security business | Disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross sale price	$ 1.8		$ 1.8
Net gain on sale of business	0.5
Cash consideration received	$ 1.0
Period of business performance and retention of current customers for payment of contingent consideration	18 months
Fair value of contingent consideration receivable	$ 0.5