The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

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- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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- Definition

Interest rate stated in the contractual debt agreement.

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- Definition

Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings.

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Shares Issued, Price Per Share

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Debt - Bridge Loans Narrative (Details) (USD $)	12 Months Ended					0 Months Ended	12 Months Ended
Debt - Bridge Loans Narrative (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jul. 27, 2012	Nov. 29, 2010 IPO [Member]	Nov. 29, 2010 Bridge Loan [Member]	Dec. 31, 2010 Bridge Loan [Member]	Jul. 31, 2010 Bridge Loan [Member]
Debt Instrument [Line Items]
Debt instrument, outstanding								$ 15,000,000
Interest rate								8.00%
Shares issued from conversion of debt						3,873,756
Purchase price of common stock (in usd per share)				$ 1.99	$ 4.00
Conversion estimated fair value						8,182,000
Long-term debt interest expense	$ 6,708,000	$ 5,562,000	$ 4,727,000				$ 4,696,000