Condensed Consolidating Financial Statements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Mar. 31, 2012
Current assets:
Cash and cash equivalents	$ 53,155	$ 95,978	$ 187,846	$ 210,521
Accounts receivable, net	101,254	96,564
Inventories, net	217,543	205,615
Prepaid expenses and other	39,377	41,101
Deferred income taxes	4,250	4,167
Total current assets	415,579	443,425
Property and equipment, net	309,877	304,508
Investment in NEC TOKIN	48,709	52,738
Goodwill	35,584	35,584
Intangible assets, net	38,310	38,646
Restricted cash	15,851	17,397
Deferred income taxes	8,321	7,994
Other assets	8,939	11,299
Total assets	881,170	911,591
Current liabilities:
Current portion of long-term debt	7,648	10,793
Accounts payable, trade	89,854	73,669
Accrued expenses	83,313	95,944
Income taxes payable and deferred income taxes	2,063	1,074
Total current liabilities	182,878	181,480
Long-term debt, less current portion	375,645	372,707
Other non-current obligations	69,584	71,946
Deferred income taxes	8,694	8,542
Stockholders' equity	244,369	276,916
Total liabilities and stockholders' equity	881,170	911,591
Parent
Current assets:
Cash and cash equivalents	8,822	17,202	8,432	7,933
Intercompany receivable	298,203	287,513
Prepaid expenses and other	3,182	3,186
Total current assets	310,207	307,901
Property and equipment, net	344	361
Investment in subsidiaries	399,792	423,695
Other assets	6,410	6,741
Long-term intercompany receivable	77,549	75,919
Total assets	794,302	814,617
Current liabilities:
Current portion of long-term debt	6,391	9,561
Accounts payable, trade	137	61
Intercompany payable	122,753	100,947
Accrued expenses	28,360	37,490
Total current liabilities	157,641	148,059
Long-term debt, less current portion	375,084	372,157
Other non-current obligations	17,208	17,485
Stockholders' equity	244,369	276,916
Total liabilities and stockholders' equity	794,302	814,617
Guarantor Subsidiaries
Condensed Consolidating Balance Sheet
Percentage of ownership interest	100.00%
Current assets:
Cash and cash equivalents	26,088	52,056	158,239	178,205
Accounts receivable, net	46,683	42,051
Intercompany receivable	274,135	251,524
Inventories, net	133,048	126,286
Prepaid expenses and other	17,170	13,564
Deferred income taxes	990	578
Total current assets	498,114	486,059
Property and equipment, net	113,476	111,584
Investment in NEC TOKIN	48,709	52,738
Investment in subsidiaries	424,386	424,386
Goodwill	35,584	35,584
Intangible assets, net	29,417	29,763
Restricted cash	15,851	17,397
Deferred income taxes	1,500	1,500
Other assets	1,146	3,173
Long-term intercompany receivable	57,549	56,338
Total assets	1,225,732	1,218,522
Current liabilities:
Current portion of long-term debt	15	16
Accounts payable, trade	44,246	37,444
Intercompany payable	510,941	481,707
Accrued expenses	14,643	19,615
Income taxes payable and deferred income taxes	3,124	3,046
Total current liabilities	572,969	541,828
Other non-current obligations	2,975	3,899
Deferred income taxes	3,219	2,808
Long-term intercompany payable	77,549	75,919
Stockholders' equity	569,020	594,068
Total liabilities and stockholders' equity	1,225,732	1,218,522
Non-Guarantor Subsidiaries
Condensed Consolidating Balance Sheet
Percentage of capital stock	51.00%
Current assets:
Cash and cash equivalents	18,245	26,720	21,175	24,383
Accounts receivable, net	54,571	54,513
Intercompany receivable	175,292	150,376
Inventories, net	84,495	79,329
Prepaid expenses and other	21,977	27,303
Deferred income taxes	3,260	3,589
Total current assets	357,840	341,830
Property and equipment, net	196,057	192,563
Investment in subsidiaries	10,750	10,750
Intangible assets, net	8,893	8,883
Deferred income taxes	6,821	6,494
Other assets	1,383	1,385
Long-term intercompany receivable	2,800	2,800
Total assets	584,544	564,705
Current liabilities:
Current portion of long-term debt	1,242	1,216
Accounts payable, trade	45,471	36,164
Intercompany payable	113,936	106,759
Accrued expenses	40,310	38,839
Income taxes payable and deferred income taxes	1,891	980
Total current liabilities	202,850	183,958
Long-term debt, less current portion	561	550
Other non-current obligations	49,401	50,562
Deferred income taxes	5,475	5,734
Long-term intercompany payable	60,349	59,138
Stockholders' equity	265,908	264,763
Total liabilities and stockholders' equity	584,544	564,705
Reclassifications and Eliminations
Current assets:
Intercompany receivable	(747,630)	(689,413)
Prepaid expenses and other	(2,952)	(2,952)
Total current assets	(750,582)	(692,365)
Investment in subsidiaries	(834,928)	(858,831)
Long-term intercompany receivable	(137,898)	(135,057)
Total assets	(1,723,408)	(1,686,253)
Current liabilities:
Intercompany payable	(747,630)	(689,413)
Income taxes payable and deferred income taxes	(2,952)	(2,952)
Total current liabilities	(750,582)	(692,365)
Long-term intercompany payable	(137,898)	(135,057)
Stockholders' equity	(834,928)	(858,831)
Total liabilities and stockholders' equity	$ (1,723,408)	$ (1,686,253)
10.5% Senior Notes
Condensed Consolidating Balance Sheet
Interest rate of senior notes (as a percent)	10.50%	10.50%