Acquisitions and Divestitures Divestitures (Details) - USD ($)	3 Months Ended										12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cost of sales
Income tax expense											$ 9,600,000	$ 6,200,000	$ 8,300,000
Income from discontinued operations, net of tax			$ 2,600,000	$ 4,500,000	$ 4,300,000	$ 4,500,000	$ 2,800,000	$ 1,800,000	$ 2,200,000	$ 2,900,000	15,900,000	9,700,000	13,700,000
ASSETS
Allowance for doubtful accounts			4,000,000				2,100,000				4,000,000	2,100,000
Current assets held for sale			148,200,000				106,200,000				148,200,000	106,200,000
Goodwill													33,900,000
LIABILITIES
Current liabilities held for sale			49,400,000				39,100,000				$ 49,400,000	39,100,000
Electronic Security [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses			$ 350,000,000
Divestiture Agreed Upon Contingent Payment			10.00%								10.00%
Divestiture Credit For Transition Services			$ 6,000,000								$ 6,000,000
Net sales
Services											221,500,000	204,800,000	216,300,000
Products											127,000,000	111,400,000	58,600,000
Revenue, Net											348,500,000	316,200,000	274,900,000
Cost of sales
Services											181,100,000	172,600,000	174,500,000
Products											102,200,000	90,500,000	46,100,000
Cost of Goods and Services Sold											283,300,000	263,100,000	220,600,000
Gross profit											65,200,000	53,100,000	54,300,000
Selling and administrative expense											39,700,000	37,200,000	32,300,000
Income from discontinued operations before taxes											25,500,000	15,900,000	22,000,000
Income tax expense											9,600,000	6,200,000	8,300,000
Income from discontinued operations, net of tax											15,900,000	9,700,000	$ 13,700,000
ASSETS
Cash and cash equivalents			(1,500,000)				(4,100,000)				(1,500,000)	(4,100,000)
Trade receivables, less allowances for doubtful accounts of $4.0 and $2.1, respectively			75,600,000				74,600,000				75,600,000	74,600,000
Inventories			29,100,000				30,400,000				29,100,000	30,400,000
Prepaid expenses			900,000				800,000				900,000	800,000
Other current assets			5,000,000				4,500,000				5,000,000	4,500,000
Current assets held for sale			109,100,000				106,200,000				109,100,000	106,200,000
Property, plant and equipment, net			5,200,000				3,800,000				5,200,000	3,800,000
Goodwill			33,900,000				33,900,000				33,900,000	33,900,000
Other assets			0				1,000,000				0	1,000,000
Assets held for sale			148,200,000				144,900,000				148,200,000	144,900,000
LIABILITIES
Accounts payable			24,800,000				13,100,000				24,800,000	13,100,000
Deferred revenue			13,300,000				14,300,000				13,300,000	14,300,000
Payroll and other benefits liabilities			6,600,000				7,400,000				6,600,000	7,400,000
Other current liabilities			4,700,000				4,300,000				4,700,000	4,300,000
Current liabilities held for sale			49,400,000				39,100,000				49,400,000	39,100,000
Other long-term liabilities			0				100,000				0	100,000
Liabilities held for sale			$ 49,400,000				$ 39,200,000				$ 49,400,000	39,200,000
Eras Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses					$ 1,000,000				$ 20,000,000
LIABILITIES
Gain (loss) on disposal												$ 13,700,000
Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses		$ 350,000,000
Subsequent Event [Member] | Electronic Security [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses		35,000,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax		$ 245,000,000
Subsequent Event [Member] | Eras Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses	$ 1,000,000.0