Investment In Partnerships (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Final principal installment paid	$ 240
Operating expenses	13,507	13,231	12,709
Gain on sale of investment in partnership		822
Hearing Instrument Manufacturers Patent Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Purchase price	1,800
Ownership interest	9.00%
Number of patents	45
Acquired finite-lived intangible assets	1,475
Increases (decrease) in carrying amount of investment	(204)	(166)	(34)
Operating expenses	58	50	0
Carrying amount of partnership	569	773
Remaining amount to amortize, 2014	195
Remaining amount to amortize, 2015	195
Remaining amount to amortize, 2016	195
Global Coils [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest		50.00%
Increases (decrease) in carrying amount of investment	50	208
Carrying amount of partnership	0	380
Proceeds from sale of Global Coils	426	426
Gain on sale of investment in partnership	822	822
Receivable from related party		376
Patents [Member] | Hearing Instrument Manufacturers Patent Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Acquired finite-lived intangible assets	345
Acquired finite-lived intangible assets amortization period	10 years
Non-Exclusive Patents [Member] | Hearing Instrument Manufacturers Patent Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Acquired finite-lived intangible assets	$ 1,130