Stock Options Narrative (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Stock Options [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Unrecognized stock-based compensation expense for stock options	$ 2,214
Unrecognized stock-based compensation expense, stock options, upon change in control, value	548
Unrecognized stock-based compensation expense, stock options, upon change in control, shares	275
Unrecognized stock-based compensation expense, stock options, amortized for weighted average period	$ 1,667
Weighted average period for amortization of unrecognized stock-based compensation, stock options	1 year 11 months
Less than 10% Stockholder [Member] | Employees [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Stockholder's ownership interest	10.00%
Incentive stock options, exercise price, percent of fair value (less than)	100.00%
10% or more Stockholder [Member] | Employees [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Stockholder's ownership interest	10.00%
Incentive stock options, exercise price, percent of fair value (less than)	110.00%