Quarterly Financial Data (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 50,736		$ 38,385		$ 38,175		$ 38,905		$ 45,954		$ 34,666		$ 37,626		$ 33,415		$ 166,201		$ 151,661		$ 157,068
Cost of goods sold	34,116		23,411		24,803		25,878		31,167		20,294		24,314		20,734		108,208		96,509		95,394
Gross profit	16,620		14,974		13,372		13,027		14,787		14,372		13,312		12,681		57,993		55,152		61,674
Operating expenses:
Product development and engineering	5,652		4,627		4,454		4,648		4,233		4,023		3,389		3,699		19,381		15,344		14,486
Selling, general and administrative	10,840		10,308		9,453		12,392		13,391		11,414		11,167		12,627		42,993		48,599		50,905
Impairment of goodwill																	0		1,056		0
Total operating expenses	16,492		14,935		13,907		17,040		17,625		16,492		14,556		16,326		62,374		64,999		65,391
Operating income (loss)	128		39		(535)		(4,013)		(2,838)		(2,120)		(1,244)		(3,645)		(4,381)		(9,847)		(3,717)
Interest expense	(112)		(41)		(241)		(132)		(150)		(52)		(191)		(208)		(526)		(601)		(856)
Gain from settlement of deferred consideration obligation	(190)		(132)		(102)				0		0		2,314		0		0		2,314		0
Other income (loss), net							17		(117)		(17)		(82)		162		(407)		(54)		30
Income (loss) from continuing operations before income taxes	(174)		(134)		(878)		(4,128)		(3,105)		(2,189)		797		(3,691)		(5,314)		(8,188)		(4,543)
Provision (benefit) for income taxes	1,075		12		115		306		1,077		(869)		296		(1,517)		1,508		(1,013)		(1,191)
Loss from continuing operations									(4,182)		(1,320)		501		(2,174)		(6,822)		(7,175)		(3,352)
Gain (loss) from discontinued operations									9,788		(2,108)		(630)		5,789		0		12,839		(3,474)
Net income (loss) attributable to MRV	$ (1,249)		$ (146)		$ (993)		$ (4,434)		$ 5,606		$ (3,428)		$ (129)		$ 3,615		$ (6,822)		$ 5,664		$ (6,826)
Net income (loss) attributable to MRV per share — basic:
From continuing operations (dollars per share)									$ (0.54)	[1]	$ (0.17)	[1]	$ 0.06	[1]	$ (0.28)	[1]	$ (0.91)	[1]	$ (0.92)	[1]	$ (0.43)	[1]
From discontinued operations (dollars per share)									$ 1.26	[1]	$ (0.27)	[1]	$ (0.08)	[1]	$ 0.73	[1]	$ 0.00	[1]	$ 1.64	[1]	$ (0.44)	[1]
Net income (loss) attributable to MRV per share — basic (1) (dollars per share)									$ 0.72	[1]	$ (0.44)	[1]	$ (0.02)	[1]	$ 0.46	[1]	$ (0.91)	[1]	$ 0.72	[1]	$ (0.87)	[1]
Net income (loss) attributable to MRV per share — diluted:
From continuing operations (dollars per share)									$ (0.54)	[1]	$ (0.17)	[1]	$ 0.06	[1]	$ (0.28)	[1]	$ (0.91)	[1]	$ (0.92)	[1]	$ (0.43)	[1]
From discontinued operations (dollars per share)									$ 1.26	[1]	$ (0.27)	[1]	$ (0.08)	[1]	$ 0.73	[1]	$ 0.00	[1]	$ 1.64	[1]	$ (0.44)	[1]
Net income (loss) attributable to MRV per share — diluted (1) (dollars per share)	$ (0.17)	[1]	$ (0.02)	[1]	$ (0.13)	[1]	$ (0.59)	[1]	$ 0.72	[1]	$ (0.44)	[1]	$ (0.02)	[1]	$ 0.46	[1]	$ (0.91)	[1]	$ 0.72		$ (0.87)	[1]
Basic and diluted weighted average shares	7,443		7,522		7,585		7,568		7,760		7,766		7,887		7,887		7,484		7,813		7,878
Diluted weighted average shares									7,760		7,766		7,887		7,896		7,484		7,817		7,878

[1] Amounts may not add due to rounding.