Summary of Significant Accounting Policies - Part Three (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended				9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2014 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2014 Employee Stock Option [Member]	Sep. 30, 2014 Amended and Restated 1997 Incentive and Capital Accumulation Plan [Member]	Sep. 30, 2014 The Incentive Plan [Member]	Jun. 02, 2011 The Incentive Plan [Member]	Jun. 01, 2011 The Incentive Plan [Member]
Movement in Standard Product Warranty Accrual [Roll Forward]
Accrued warranty reserve, beginning of period		$ 497	$ 639	$ 549	$ 806
Estimated warranty expense	467	161	933	376
Amounts charged against warranty reserve	(234)	(202)	(533)	(469)
Accrued warranty reserve, end of period	1,039	456	1,039	456	806
Increase in deferred tax asset valuation allowance			747
Valuation allowance for deferred tax assets	130,979		130,979
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period									10 years
Common Stock, Par or Stated Value Per Share	$ 1		$ 1			$ 1					$ 1.00
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized											2,200,000	1,500,000
Common Stock, Capital Shares Reserved for Future Issuance										1,050,722
Share-Based Compensation Arrangement By Share-Based Payment Award, Aggregate Number Of Shares Granted										818,858
Shares available for grant (in shares)										231,864
Unrecognized compensation expense	2,010		2,010
Weighted average expense recognition period (in years)							2 years	3 years
Unrecognized compensation expense for unvested stock options	$ 3,831		$ 3,831