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ACQUISITIONS AND DISPOSITION (Details) - USD ($) $ / shares in Units, $ in Thousands |  |  |  | 3 Months Ended | 6 Months Ended |
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Jan. 23, 2015 | Jul. 25, 2014 | Jun. 19, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Dec. 31, 2014 | [1]
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |
Payment for acquisitions, net of cash acquired |  |  |  |  |  |  | $ 0 | $ 109,879 |
Revenues |  |  |  |  | $ 145,658 | $ 99,439 | 287,673 | 182,085 |
Operating income (loss) |  |  |  |  | 7,452 | 3,714 | 16,498 | 6,595 |
Liabilities assumed [Abstract] |  |  |  |  |  |  |  |  |
Goodwill |  |  |  |  | 122,287 |  | 122,287 |  | $ 118,369
Network Power Systems [Member] |  |  |  |  |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |
Proceeds from sale of business |  | $ 9,000 |  |  |  |  |  |  |
Proceeds from sale of business in escrow |  | $ 1,000 |  |  |  |  |  |  |
Number of months of manufacturing service agreement |  | 24 months |  |  |  |  |  |  |
Deferred revenue |  | $ 9,000 |  |  |  |  |  |  |
Disposal of assets, net sales |  |  |  |  | 1,100 |  | 2,100 |  |
Power Solutions [Member] |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |
Payment for acquisitions, net of cash acquired |  |  |  | $ 109,900 |  |  |  |  |
Percentages of owned joint venture investment (in hundredths) |  |  |  | 49.00% |  |  |  |  |
Deductible for tax purposes from goodwill |  |  |  |  | 56,300 |  | 56,300 |  |
Revenues |  |  |  |  |  | 7,200 |  | 7,200 |
Operating income (loss) |  |  |  |  |  | (1,000) |  | (1,000) |
Assets acquired [Abstract] |  |  |  |  |  |  |  |  |
Cash |  |  |  | $ 20,912 |  |  |  |  |
Accounts receivable |  |  |  | 29,389 |  |  |  |  |
Inventories |  |  |  | 36,429 |  |  |  |  |
Other current assets |  |  |  | 7,350 |  |  |  |  |
Property, plant and equipment | [2] |  |  | 27,115 |  |  |  |  |
Intangible assets |  |  |  | 33,220 |  |  |  |  |
Other assets |  |  |  | 19,171 |  |  |  |  |
Total identifiable assets |  |  |  | 173,586 |  |  |  |  |
Liabilities assumed [Abstract] |  |  |  |  |  |  |  |  |
Accounts payable |  |  |  | (26,180) |  |  |  |  |
Accrued expenses |  |  |  | (25,545) |  |  |  |  |
Other current liabilities |  |  |  | 223 |  |  |  |  |
Noncurrent liabilities | [3] |  |  | (49,260) |  |  |  |  |
Total liabilities assumed |  |  |  | (100,762) |  |  |  |  |
Net identifiable assets acquired |  |  |  | 72,824 |  |  |  |  |
Goodwill |  |  |  | 57,968 |  |  |  |  |
Net assets acquired |  |  |  | 130,792 |  |  |  |  |
Consideration transferred [Abstract] |  |  |  |  |  |  |  |  |
Cash Paid |  |  |  | 130,792 |  |  |  |  |
Assumption of liability |  |  |  | 0 |  |  |  |  |
Fair value of consideration transferred |  |  |  | 130,792 |  |  |  |  |
Deferred consideration |  |  |  | 0 |  |  |  |  |
Total consideration paid |  |  |  | 130,792 |  |  |  |  |
Power Solutions [Member] | As Reported [Member] |  |  |  |  |  |  |  |  |
Assets acquired [Abstract] |  |  |  |  |  |  |  |  |
Cash |  |  |  | 20,912 |  |  |  |  |
Accounts receivable |  |  |  | 29,389 |  |  |  |  |
Inventories |  |  |  | 36,429 |  |  |  |  |
Other current assets |  |  |  | 7,350 |  |  |  |  |
Property, plant and equipment |  |  |  | 28,175 |  |  |  |  |
Intangible assets |  |  |  | 33,220 |  |  |  |  |
Other assets |  |  |  | 19,171 |  |  |  |  |
Total identifiable assets |  |  |  | 174,646 |  |  |  |  |
Liabilities assumed [Abstract] |  |  |  |  |  |  |  |  |
Accounts payable |  |  |  | (26,180) |  |  |  |  |
Accrued expenses |  |  |  | (25,545) |  |  |  |  |
Other current liabilities |  |  |  | 223 |  |  |  |  |
Noncurrent liabilities |  |  |  | (42,062) |  |  |  |  |
Total liabilities assumed |  |  |  | (93,564) |  |  |  |  |
Net identifiable assets acquired |  |  |  | 81,082 |  |  |  |  |
Goodwill |  |  |  | 49,710 |  |  |  |  |
Net assets acquired |  |  |  | 130,792 |  |  |  |  |
Consideration transferred [Abstract] |  |  |  |  |  |  |  |  |
Cash Paid |  |  |  | 130,792 |  |  |  |  |
Assumption of liability |  |  |  | 0 |  |  |  |  |
Fair value of consideration transferred |  |  |  | 130,792 |  |  |  |  |
Deferred consideration |  |  |  | 0 |  |  |  |  |
Total consideration paid |  |  |  | 130,792 |  |  |  |  |
Power Solutions [Member] | Measurement Period Adjustments [Member] |  |  |  |  |  |  |  |  |
Assets acquired [Abstract] |  |  |  |  |  |  |  |  |
Cash |  |  |  | 0 |  |  |  |  |
Accounts receivable |  |  |  | 0 |  |  |  |  |
Inventories |  |  |  | 0 |  |  |  |  |
Other current assets |  |  |  | 0 |  |  |  |  |
Property, plant and equipment | [2] |  |  | (1,060) |  |  |  |  |
Intangible assets |  |  |  | 0 |  |  |  |  |
Other assets |  |  |  | 0 |  |  |  |  |
Total identifiable assets |  |  |  | (1,060) |  |  |  |  |
Liabilities assumed [Abstract] |  |  |  |  |  |  |  |  |
Accounts payable |  |  |  | 0 |  |  |  |  |
Accrued expenses |  |  |  | 0 |  |  |  |  |
Other current liabilities |  |  |  | 0 |  |  |  |  |
Noncurrent liabilities | [3] |  |  | (7,198) |  |  |  |  |
Total liabilities assumed |  |  |  | (7,198) |  |  |  |  |
Net identifiable assets acquired |  |  |  | (8,258) |  |  |  |  |
Goodwill |  |  |  | 8,258 |  |  |  |  |
Net assets acquired |  |  |  | 0 |  |  |  |  |
Consideration transferred [Abstract] |  |  |  |  |  |  |  |  |
Cash Paid |  |  |  | 0 |  |  |  |  |
Assumption of liability |  |  |  | 0 |  |  |  |  |
Fair value of consideration transferred |  |  |  | 0 |  |  |  |  |
Deferred consideration |  |  |  | 0 |  |  |  |  |
Total consideration paid |  |  |  | $ 0 |  |  |  |  |
Connectivity Solutions [Member] |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |
Payment for acquisitions, net of cash acquired |  |  | $ 98,800 |  |  |  |  |  |
Assets acquired [Abstract] |  |  |  |  |  |  |  |  |
Cash | [4] |  | 6,544 |  |  |  |  |  |
Accounts receivable | [4] |  | 9,375 |  |  |  |  |  |
Inventories | [4] |  | 17,632 |  |  |  |  |  |
Other current assets | [4] |  | 2,615 |  |  |  |  |  |
Property, plant and equipment | [4] |  | 9,900 |  |  |  |  |  |
Intangible assets | [4] |  | 40,000 |  |  |  |  |  |
Other assets | [4] |  | 2,345 |  |  |  |  |  |
Total identifiable assets | [4] |  | 88,411 |  |  |  |  |  |
Liabilities assumed [Abstract] |  |  |  |  |  |  |  |  |
Accounts payable | [4] |  | (10,682) |  |  |  |  |  |
Accrued expenses | [4] |  | (5,307) |  |  |  |  |  |
Other current liabilities | [4] |  | (57) |  |  |  |  |  |
Noncurrent liabilities | [4] |  | (17,314) |  |  |  |  |  |
Total liabilities assumed | [4] |  | (33,360) |  |  |  |  |  |
Net identifiable assets acquired | [4] |  | 55,051 |  |  |  |  |  |
Goodwill | [4] |  | 50,306 |  |  |  |  |  |
Net assets acquired | [4] |  | 105,357 |  |  |  |  |  |
Consideration transferred [Abstract] |  |  |  |  |  |  |  |  |
Cash Paid | [4] |  | 105,357 |  |  |  |  |  |
Assumption of liability | [4] |  | 0 |  |  |  |  |  |
Fair value of consideration transferred | [4] |  | 105,357 |  |  |  |  |  |
Deferred consideration | [4] |  | 0 |  |  |  |  |  |
Total consideration paid | [4] |  | $ 105,357 |  |  |  |  |  |
2014 Acquired Companies [Member] |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |
Acquisition-related costs |  |  |  |  | 100 | 1,500 | 500 | 1,500 |
Revenues |  |  |  |  | 58,400 |  | 117,200 |  |
Operating income (loss) |  |  |  |  | (1,200) |  | 4,400 |  |
Assets acquired [Abstract] |  |  |  |  |  |  |  |  |
Cash |  |  |  |  | 27,456 |  | 27,456 |  |
Accounts receivable |  |  |  |  | 38,764 |  | 38,764 |  |
Inventories |  |  |  |  | 54,061 |  | 54,061 |  |
Other current assets |  |  |  |  | 9,965 |  | 9,965 |  |
Property, plant and equipment |  |  |  |  | 37,015 |  | 37,015 |  |
Intangible assets |  |  |  |  | 73,220 |  | 73,220 |  |
Other assets |  |  |  |  | 21,516 |  | 21,516 |  |
Total identifiable assets |  |  |  |  | 261,997 |  | 261,997 |  |
Liabilities assumed [Abstract] |  |  |  |  |  |  |  |  |
Accounts payable |  |  |  |  | (36,862) |  | (36,862) |  |
Accrued expenses |  |  |  |  | (30,852) |  | (30,852) |  |
Other current liabilities |  |  |  |  | 166 |  | 166 |  |
Noncurrent liabilities |  |  |  |  | (66,574) |  | (66,574) |  |
Total liabilities assumed |  |  |  |  | (134,122) |  | (134,122) |  |
Net identifiable assets acquired |  |  |  |  | 127,875 |  | 127,875 |  |
Goodwill |  |  |  |  | 108,274 |  | 108,274 |  |
Net assets acquired |  |  |  |  | $ 236,149 |  | 236,149 |  |
Consideration transferred [Abstract] |  |  |  |  |  |  |  |  |
Cash Paid |  |  |  |  |  |  | 236,149 |  |
Assumption of liability |  |  |  |  |  |  | 0 |  |
Fair value of consideration transferred |  |  |  |  |  |  | 236,149 |  |
Deferred consideration |  |  |  |  |  |  | 0 |  |
Total consideration paid |  |  |  |  |  |  | $ 236,149 |  |
Unaudited Pro forma Consolidated Results of Operations [Abstract] |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  | 156,842 |  | 317,479 |
Net loss |  |  |  |  |  | $ (3,057) |  | $ (1,399) |
2014 Acquired Companies [Member] | Class A [Member] |  |  |  |  |  |  |  |  |
Unaudited Pro forma Consolidated Results of Operations [Abstract] |  |  |  |  |  |  |  |  |
Loss per common share - basic and diluted (in dollars per share) |  |  |  |  |  | $ (0.26) |  | $ (0.13) |
2014 Acquired Companies [Member] | Class B [Member] |  |  |  |  |  |  |  |  |
Unaudited Pro forma Consolidated Results of Operations [Abstract] |  |  |  |  |  |  |  |  |
Loss per common share - basic and diluted (in dollars per share) |  |  |  |  |  | $ (0.27) |  | $ (0.12) |
[1] | Revised
[2] | Represents the purchase accounting adjustments reflecting the finalization of the acquisition-date fair values of property, plant and equipment associated with completion of third-party valuations.
[3] | Represents the impact to deferred taxes reflecting the finalization of the allocation of identifiable intangible assets acquired.
[4] | 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.

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