Convertible Notes Long Term Debt and Credit Facility (Details Textual) (USD $)	1 Months Ended			2 Months Ended	3 Months Ended			6 Months Ended					3 Months Ended	1 Months Ended		6 Months Ended		3 Months Ended	1 Months Ended		6 Months Ended			6 Months Ended		3 Months Ended
	Nov. 30, 2011	Sep. 23, 2011	Jun. 30, 2011	Sep. 23, 2011	Jun. 30, 2011	Mar. 31, 2011	Mar. 31, 2010	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Feb. 29, 2008	Feb. 11, 2008	Mar. 31, 2010 Term loan [Member]	May 31, 2011 2008 Notes [Member]	Feb. 14, 2008 2008 Notes [Member]	Jun. 30, 2012 2008 Notes [Member]	Jun. 25, 2012 2008 Notes [Member]	Mar. 31, 2011 Senior credit facility [Member]	Jan. 31, 2012 2010 Notes [Member]	Feb. 14, 2008 2010 Notes [Member]	Jun. 30, 2012 2010 Notes [Member]	Jan. 05, 2012 2010 Notes [Member]	Mar. 31, 2010 2010 Notes [Member]	Jun. 30, 2012 Exchange agreement [Member]	Mar. 31, 2010 Exchange agreement [Member]	Mar. 31, 2010 Annual interest rate 12.5% [Member] Term loan [Member]	Sep. 23, 2011 Letters of Credit Sublimit [Member]	Jun. 30, 2012 Federal funds open rate [Member]	Jun. 30, 2012 One-Month LIBOR Rate [Member]	Jun. 30, 2012 One two or three month LIBOR rate [Member]
Line of Credit Facility [Line Items]
Credit facility, current borrowing capacity		$ 35,000,000		$ 35,000,000				$ 0
Outstanding amount of credit facility								0
Credit facility, remaining borrowing capacity																											5,000,000
Credit facility, variable percentage rate spread								1.00%																				1.50%	2.00%	2.00%
Debt instrument, principal amount															115,000,000
Term loan, face amount													40,000,000
Convertible notes, interest rate								5.25%							5.25%					5.25%
Convertible notes maturity date							Nov. 01, 2012									Feb. 15, 2028					Feb. 15, 2028
Nonconvertible debt borrowing interest rate																11.50%
Expected term for accretion of associated debt discount (in years)																5 years
Contractual call/put options, exercisable date																Feb. 15, 2013
Discount on notes								2,269,000		6,766,000					27,800,000
Deferred tax liability on notes															10,600,000
Repurchase of senior unsecured notes																	15,000,000					36,000,000
Percentage of original principal amount of notes plus accrued and unpaid interest equalized repurchase																	102.00%					104.95%
Amount of cash premium included in loss on extinguishment of debt																	300,000					1,800,000
Debt instrument, maturity date							Nov. 01, 2012									Feb. 15, 2028					Feb. 15, 2028
Senior credit facility, value of common stock converted							50																		2,000,000
Convertible notes for each $1,000 principal amount, amount of notes exchanged																40,000,000
Convertible notes for each $1,000 principal amount, amount of aggregate consideration																					36,000,000
Redeemable price as a percentage of outstanding principal note amount								100.00%											104.95%
Amount of notes exchanged														4,500,000					36,000,000
Loss on the extinguishment of debt			2,100,000					1,000,000						1,100,000					5,400,000
Accretion of debt discount					1,200,000	1,300,000		2,031,000	2,657,000										1,800,000
Contingent interest percentage on principal amount of notes, minimum																								120.00%
Contingent interest payable rate																								0.50%
Convertible notes for each $1,000 principal amount, value of shares														4,500,000
Convertible notes for each $1,000 principal amount, number of shares														559,007
Term loan, quarterly principal payments													1,000,000					1,000,000
Term loan, annual interest rate																										12.50%
Convertible notes for each $1000 principal amount, principal amount of 2010 Notes converted																							900
Return of borrowed shares under share-based, shares	701,102
Convertible Notes Long Term Debt and Credit Facility (Textual) [Abstract]
Credit facility, expiration date		Dec. 15, 2012
Percentage Added to Federal Funds Open Rate for the Calculation of Interest on Borrowings								1.00%																				1.50%	2.00%	2.00%
Credit facility, extended maturity date		September 22, 2014
Credit facility, interest rate at period end								4.25%
Credit facility, commitment fee percentage								0.25%
Credit facility, financial covenant debt ratio upper range								110.00%
Credit facility, financial covenant debt ratio lower range								100.00%
Credit facility, covenant terms				The Credit Facility is secured by substantially all of the Company’s personal property, including accounts receivable, inventory, equipment and other intangible assets and contains customary representations, warranties, and both affirmative and negative covenants, including a financial covenant to maintain consolidated earnings before interest, taxes, depreciation and amortization (“EBITDA”) to debt ratio of 1.10 to 1.00 and an annual limit on capital expenditures. The Credit Facility restricts the payment of cash dividends on common stock. In the event of default, the Lender may accelerate the maturity date of outstanding amounts borrowed under the Credit Facility.
Credit facility, interest rate description		Interest on borrowings under the Credit Facility is calculated daily at the higher of (a) the commercial lending base rate of PNC Bank plus 1%, (b) the federal funds open rate plus 1.5%, and (c) the daily one-month LIBOR rate plus 2%. The interest rate on borrowings would have been 4.25% at June 30, 2012. The Company may elect to borrow any amount available under the Credit Facility for a term of one, two or three months at LIBOR plus 2%.
Effective tax rate								38.00%
Convertible notes for each $1,000 principal amount, volume-weighted average price of common stock rate							95.00%
Convertible notes for each $1,000 principal amount, number of preceding trading days							10 days	5 days
Convertible notes for each $1,000 principal amount, number of shares								43.9560
Convertible notes for each $1,000 principal amount, conversion price per share								$ 22.75
Share lending agreement, number of common stock shares loaned								3,800,000				3,800,000
Own share lending arrangement nominal loan fee per share											$ 0.0001
Borrowed shares outstanding								3,098,898
Share lending agreement, fair value								500,000
Share lending agreement, unamortized debt issuance costs								100,000
Common shares not subject to the share lending arrangement, fair value								28,900,000
Capital lease obligations								$ 1,990,000		$ 1,642,000