Acquisitions (Details)	12 Months Ended												0 Months Ended				12 Months Ended					0 Months Ended					12 Months Ended											0 Months Ended			0 Months Ended			0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended		12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2014 Trademarks [Member] USD ($)	Dec. 31, 2014 Technology [Member]	Dec. 31, 2014 Customer Relationships [Member]	Dec. 31, 2014 Licensing Agreements [Member]	Dec. 31, 2014 Noncompete Agreements [Member]	Dec. 31, 2014 Class A [Member] USD ($)	Dec. 31, 2013 Class A [Member] USD ($)	Dec. 31, 2014 Class B [Member] USD ($)	Dec. 31, 2013 Class B [Member] USD ($)	Jun. 19, 2014 Power Solutions [Member] USD ($)	Dec. 31, 2014 Power Solutions [Member] USD ($)	Jun. 19, 2014 Power Solutions [Member] USD ($)		Dec. 31, 2014 Power Solutions [Member] Trademarks [Member] USD ($)	Dec. 31, 2014 Power Solutions [Member] Technology [Member] USD ($)	Dec. 31, 2014 Power Solutions [Member] Customer Relationships [Member] USD ($)	Dec. 31, 2014 Power Solutions [Member] Licensing Agreements [Member] USD ($)	Dec. 31, 2014 Power Solutions [Member] Noncompete Agreements [Member] USD ($)	Jul. 25, 2014 Connectivity Solutions [Member] USD ($)		Dec. 31, 2014 Connectivity Solutions [Member] USD ($)	Jul. 25, 2014 Connectivity Solutions [Member] USD ($)		Dec. 31, 2014 Connectivity Solutions [Member] Trademarks [Member] USD ($)	Dec. 31, 2014 Connectivity Solutions [Member] Technology [Member] USD ($)	Dec. 31, 2014 Connectivity Solutions [Member] Customer Relationships [Member] USD ($)	Dec. 31, 2014 Connectivity Solutions [Member] Licensing Agreements [Member] USD ($)	Dec. 31, 2014 Connectivity Solutions [Member] Noncompete Agreements [Member] USD ($)	Dec. 31, 2014 2014 Acquired Companies [Member] USD ($)	Dec. 31, 2014 2014 Acquired Companies [Member] Technology [Member] USD ($)	Dec. 31, 2014 2014 Acquired Companies [Member] Customer Relationships [Member] USD ($)	Dec. 31, 2014 2014 Acquired Companies [Member] Licensing Agreements [Member] USD ($)	Dec. 31, 2014 2014 Acquired Companies [Member] Noncompete Agreements [Member] USD ($)	Dec. 31, 2014 2014 Acquired Companies [Member] Acquisition Date Fair Values (As adjusted) [Member] USD ($)	Mar. 09, 2012 GigaCom Interconnect [Member] USD ($)	Mar. 09, 2012 GigaCom Interconnect [Member] EUR (€)	Mar. 09, 2012 GigaCom Interconnect [Member]	Jul. 31, 2012 Fibreco [Member] USD ($)	Jul. 31, 2012 Fibreco [Member] EUR (€)	Jul. 31, 2012 Fibreco [Member]	Sep. 12, 2012 Powerbox Italy [Member] USD ($)	Sep. 12, 2012 Powerbox Italy [Member]	Sep. 12, 2012 Powerbox Italy [Member] Class B [Member]	Sep. 12, 2012 Powerbox Italy [Member] Class B [Member] USD ($)	Mar. 29, 2013 TRP [Member] USD ($)	Mar. 29, 2013 TRP [Member]	Mar. 29, 2013 TRP [Member] Acquisition Date Fair Values [Member] USD ($)	Mar. 29, 2013 TRP [Member] Acquisition Date Fair Values [Member] USD ($)	Aug. 20, 2013 Array [Member] USD ($)	Aug. 20, 2013 Array [Member]	Aug. 20, 2013 Array [Member] Measurement Period Adjustments [Member] USD ($)	Aug. 20, 2013 Array [Member] Measurement Period Adjustments [Member] USD ($)	Dec. 31, 2014 2013 Acquired Companies [Member] USD ($)	Dec. 31, 2013 2013 Acquired Companies [Member] USD ($)	Dec. 31, 2012 2013 Acquired Companies [Member] USD ($)	Dec. 31, 2013 2013 Acquired Companies [Member] Acquisition Date Fair Values (As adjusted) [Member] USD ($)
Business Acquisition [Line Items]
Payment for acquisitions, net of cash acquired	$ 208,693,000	$ 30,994,000	$ 19,410,000										$ 109,900,000									$ 98,800,000																$ 2,700,000	€ 1,700,000		$ 13,700,000	€ 8,700,000		$ 3,000,000				$ 21,000,000				$ 10,000,000
Acquisition-related costs																																7,300,000																								100,000	900,000	1,300,000
Assets acquired [Abstract]
Cash															20,912,000										6,544,000	[1]											27,456,000														8,388,000				0				8,388,000
Accounts receivable															29,389,000										9,375,000	[1]											38,764,000														11,541,000				994,000				12,535,000
Inventories															36,429,000	[2]									17,632,000	[1],[2]											54,061,000														7,355,000				993,000				8,348,000
Other current assets															7,350,000										2,615,000	[1]											9,965,000														1,619,000				428,000				2,047,000
Property, plant and equipment															28,175,000	[3]									9,900,000	[1],[3]											38,075,000														5,790,000				3,510,000				9,300,000
Intangible assets														33,220,000	33,220,000	[4]								40,000,000	40,000,000	[1],[4]						73,220,000					73,220,000														6,110,000				1,470,000				7,580,000
Other assets															19,171,000	[5]									2,345,000	[1]											21,516,000														1,349,000				1,747,000				3,096,000
Total identifiable assets															174,646,000										88,411,000	[1]											263,057,000														42,152,000				9,142,000				51,294,000
Liabilities assumed [Abstract]
Accounts payable															(26,180,000)										(10,682,000)	[1]											(36,862,000)														(8,234,000)				(676,000)				(8,910,000)
Accrued expenses															(25,545,000)	[6]									(5,307,000)	[1]											(30,852,000)														(4,465,000)				(285,000)				(4,750,000)
Other current liabilities															223,000										(57,000)	[1]											166,000														(759,000)				0				(759,000)
Noncurrent liabilities															(42,062,000)	[5],[6],[7]									(17,314,000)	[1]											(59,376,000)														(586,000)				(1,748,000)				(2,334,000)
Total liabilities assumed															(93,564,000)										(33,360,000)	[1]											(126,924,000)														(14,044,000)				(2,709,000)				(16,753,000)
Net identifiable assets acquired															81,082,000										55,051,000	[1]											136,133,000														28,108,000				6,433,000				34,541,000
Goodwill	117,573,000	18,490,000	13,559,000												49,710,000	[8]									50,306,000	[1],[6]											100,016,000														1,240,000				3,572,000				4,812,000
Net assets acquired															130,792,000										105,357,000	[1]											236,149,000														29,348,000				10,005,000				39,353,000
Consideration transferred [Abstract]
Cash Paid													130,792,000									105,357,000	[1]														236,149,000
Assumption of liability													0									0	[1]														0
Fair value of consideration transferred													130,792,000									105,357,000	[1]														236,149,000													29,348,000				10,005,000					39,353,000
Deferred consideration													0									0	[1]														0
Total consideration paid/payable													130,792,000									105,357,000	[1]														236,149,000
Estimated net set-up in fair value related to inventories														3,273,000										2,651,000								5,924,000
Estimated net set-up in fair value related to property, plant and equipment																								4,300,000
Fair Value of Identifiable Intangible Assets [Abstract]
Acquisition date fair value				8,390,000													890,000	7,800,000	12,200,000	11,800,000	530,000						7,500,000	9,000,000	22,000,000	0	1,500,000		16,800,000	34,200,000	11,800,000	2,030,000
Weighted average life					14 years	16 years	8 years	3 years
Total identifiable assets acquired														33,220,000	33,220,000	[4]								40,000,000	40,000,000	[1],[4]						73,220,000					73,220,000														6,110,000				1,470,000				7,580,000
Noncurrent liability and offsetting indemnification asset	12,000,000
Unaudited Pro forma Consolidated Results of Operations
Revenue	629,132,000	710,937,000																														134,300,000																								75,400,000	68,600,000
Net earnings	11,705,000	(65,299,000)
Income (loss) from operations	14,093,000	15,047,000	1,663,000																													(1,900,000)																								12,700,000	8,400,000
Earnings per common share - basic and diluted (in dollars per share)									$ 0.94	$ (5.52)	$ 1.02	$ (5.77)
Acquisition-related costs excluded from pro forma net earnings	14,900,000	5,900,000
Acquisition-related costs incurred but excluded from pro forma earnings during the period after tax	9,800,000	4,100,000
Acquisition of issued and outstanding capital stock (in hundredths)															100.00%																									100.00%			100.00%		100.00%				100.00%				100.00%
Cash acquired from acquisition	27,456,000	8,359,000	2,991,000																																						2,700,000			200,000
Number of restricted shares granted for acquisition (in shares)																																														30,000
Compensation expense of grant date fair value of restricted shares																																															$ 600,000

[1] The Company acquired the U.S. and U.K. entities of Connectivity Solutions on July 25, 2014 and the China entity of Connectivity Solutions on August 29, 2014. These values represent the estimated fair values as of the respective acquisition dates.

[2] The inventories noted include the following estimated net step-up in fair value: Estimated Net Step-Up in Fair Value Power Solutions $ 3,273 Connectivity Solutions 2,675 2014 Acquisitions total $ 5,948

[3] The property, plant and equipment noted above for Connectivity Solutions includes a $4.3 million step-up based on estimated acquisition-date fair value. There was no step-up for property, plant and equipment for Power Solutions since the estimated acquisition-date fair value approximated the carrying value of those assets.

[4] The preliminary fair value of identifiable intangible assets related to the 2014 Acquired Companies is shown in the table below. For those intangible assets with finite lives, the acquisition-date fair values will be amortized over their respective estimated future lives utilizing the straight-line method. Acquisition-date Fair Values Power Solutions Connectivity Solutions 2014 Acquisitions Weighted-Average Life Trademarks $ 890 $ 7,500 $ 8,390 Indefinite Customer relationships 12,200 22,000 34,200 16 years Technology 7,800 9,000 16,800 14 years License agreements 11,800 - 11,800 8 years Non-compete agreements 530 1,500 2,030 3 years Total intangible assets acquired $ 33,220 $ 40,000 $ 73,220

[5] These amounts include a $12.0 million noncurrent liability and offsetting indemnification asset related to an ongoing claim by the Arezzo Revenue Agency in Italy concerning certain tax matters related to what was then Power-One Asia Pacific Electronics Shenzhen Co. Ltd. (now Bel Power Solutions Asia Pacific Electronics Shenzhen Co. Ltd.) for the years 2004 through 2006, as further described in Note 16.

[6] The Company acquired a liability for uncertain tax positions related to various tax matters for the years 2007 through 2013. While resolution of these tax matters are being actively pursued with the applicable taxing authority, these issues remained unresolved as of the filing date of this Annual Report on Form 10-K.

[7] Deferred taxes have been established on the previously-mentioned step-ups for inventories, property, plant and equipment and intangible assets.

[8] The amount of goodwill is provisional as of the filing date, as the fair value determination of inventories acquired, and appraisals related to property, plant and equipment, various intangible assets and certain liabilities such as lease liabilities is still under review. The portion of goodwill, if any, that will be deductible for tax purposes is yet to be determined.