Summary of Significant Accounting Policies - Part Three (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended			6 Months Ended			0 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Restricted Stock Units (RSUs) [Member]	Jun. 30, 2014 Employee Stock Option [Member]	Jun. 30, 2014 Amended and Restated 1997 Incentive and Capital Accumulation Plan [Member]	Jun. 02, 2011 The Incentive Plan [Member]	Jun. 30, 2014 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	$ 833	$ 453	$ 638	$ 549
Estimated warranty expense	84	147	467	255
Amounts charged against warranty reserve	(111)	(103)	(299)	(307)
Accrued warranty reserve, end of period	806	497	806	497
Increase in deferred tax asset valuation allowance			1,641
Valuation allowance for deferred tax assets	131,873		131,873
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
Increase decrease in authorized shares under incentive plan									700,000
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										810,020
Shares available for grant (in shares)										240,702
Unrecognized compensation expense	2,263		2,263
Weighted average expense recognition period (in years)						1 year 8 months 1 day	2 years 1 month 6 days
Unrecognized compensation expense for unvested stock options	$ 4,154		$ 4,154