v2.4.0.6

Stockholders' Equity (Details Textual) (USD $)	3 Months Ended				3 Months Ended			1 Months Ended		3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Oct. 31, 2011	Mar. 31, 2013 April 2013 [Member]	Mar. 31, 2013 Stock Options [Member]	Mar. 31, 2012 Stock Options [Member]	Mar. 31, 2013 Restricted Stock [Member]	May 31, 2012 2002 Stock Incentive Plan [Member]	Mar. 31, 2013 2002 Stock Incentive Plan [Member] Stock Options [Member]	Mar. 31, 2013 Employee Stock Purchase Plan [Member]	Mar. 31, 2012 Employee Stock Purchase Plan [Member]	Mar. 31, 2013 Employee Stock Purchase Plan [Member] Stock Options [Member]	Mar. 31, 2012 Employee Stock Purchase Plan [Member] Stock Options [Member]	Mar. 31, 2013 Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase the number of shares under the 2002 Stock Incentive Plan								1,800,000
Weighted-average grant date fair value of stock options					$ 21.92
Intrinsic value of options exercised					$ 200,000	$ 100,000
Unrecognized compensation cost					8,800,000
Weighted-average period in which cost is expected to be recognized					2 years 10 months 24 days		1 year 8 months 9 days
Cash received from options exercised												300,000	200,000
Shares available for future option grants									1,500,000.0
Weighted-average grant-date fair value of restricted stock							$ 21.92
Unrecognized compensation cost, restricted stock							1,400,000
Employee Stock Purchase Plan [Abstract]
Shares allowed to purchase in employee stock purchase plan										1,250
Offering period of shares in employee stock purchase plan										6 months
Percentage of purchase price of stock										85.00%
Discount rate										15.00%
Stock-based compensation expense	1,124,000	709,000								5,200	5,900
Shares available for future purchases										86,528
Warrants [Abstract]
Warrants outstanding				163,568
Exercise price of warrants				179.40
Warrants to purchase number of shares				129,360
Public Offering [Abstract]
Equity, reserved for issuance			30,000,000
Stock issued, shares	302,750
Proceeds from issuance of common stock														$ 5,500,000

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Registration Statement Form S-3, Common Stock Issuance and Sale Authorized

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The total cash inflow associated with the amount received from holders to acquire the entity's shares under incentive and share awards, including stock option exercises. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The highest quantity of shares an employee can purchase under the plan per period.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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