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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount classified as assets attributable to disposal group held for sale or disposed of.

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Amount after tax of income (loss) from continuing operations attributable to the parent.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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Amount of income (loss) from continuing operations, nonoperating income (expense) and income (loss) from equity method investments, before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of interest income (expense).

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of interest revenue (income derived from investments in debt securities and on cash and cash equivalents) net of interest expense (cost of borrowed funds accounted for as interest).

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
Segment Information (Details) $ in Millions	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) segments	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information
Number of reportable segments \| segments			2
Assets	$ 1,552.7		$ 1,552.7		$ 1,549.8
Revenues	188.4	$ 164.4	366.9	$ 332.7
Reconciliation from Segment Totals to Consolidated [Abstract]
Revenues	188.4	164.4	366.9	332.7
Reconciliation of Net Earnings from Segments [Abstract]
Interest expense, net	4.1	5.1	8.1	10.3
Earnings (loss) before income taxes and discontinued operations	5.8	(24.2)	6.2	(29.7)
Provision for income taxes	1.4	6.7	2.2	6.2
Earnings (loss) from continuing operations	4.4	(30.9)	4.0	(35.9)
Assets of discontinued operations	0.2		0.2		1.7
Asia
Segment Reporting Information
Revenues	131.8	117.9	257.8	242.8
United States
Segment Reporting Information
Revenues	32.4	25.3	62.0	48.4
Europe
Segment Reporting Information
Revenues	21.7	18.8	42.2	37.2
Other Americas
Segment Reporting Information
Revenues	0.9	1.0	1.8	1.8
Other Geographical Locations
Segment Reporting Information
Revenues	1.6	1.4	3.1	2.5
Operating Segments
Reconciliation of Net Earnings from Segments [Abstract]
Earnings (loss) before interest and income taxes	23.7	(2.9)	42.2	10.3
Operating Segments \| Audio
Segment Reporting Information
Assets	1,418.1		1,418.1		1,430.9
Reconciliation from Segment Totals to Consolidated [Abstract]
Revenues	151.8	138.1	298.2	282.3
Reconciliation of Net Earnings from Segments [Abstract]
Earnings (loss) before interest and income taxes	17.3	(7.1)	29.6	1.8
Operating Segments \| Precision Devices
Segment Reporting Information
Assets	122.4		122.4		103.4
Reconciliation from Segment Totals to Consolidated [Abstract]
Revenues	36.6	26.3	68.7	50.4
Reconciliation of Net Earnings from Segments [Abstract]
Earnings (loss) before interest and income taxes	6.4	4.2	12.6	8.5
Corporate
Segment Reporting Information
Assets	12.0		12.0		$ 13.8
Reconciliation of Net Earnings from Segments [Abstract]
Corporate expense / other	13.8	16.2	27.9	29.7
Interest expense, net	$ 4.1	$ 5.1	$ 8.1	$ 10.3