Subsequent Events	6 Months Ended
Jun. 30, 2012
Subsequent Events [Abstract]
Subsequent events	Subsequent Events On July 25, 2012, OSI announced the commencement of a tender offer for all of its outstanding senior notes. On August 13, 2012, OSI accepted for payment $102.2 million, or 41.2%, of the aggregate principal amount of its 10% senior notes, using a portion of the net proceeds from the Company’s initial public offering. OSI paid $106.8 million for the senior notes tendered, which included $2.9 million of prepayment premium and early tender incentive fees and $1.7 million of accrued interest. Further, on August 13, 2012, the remaining senior notes were called for redemption at 102.5% of the principal amount outstanding plus accrued interest, up to but not including such date of redemption. OSI deposited the full funds for the redemption with the trustee under the indenture governing the senior notes, which was comprised of the rest of the Company’s net proceeds from its initial public offering and cash on hand, and the senior notes obligation was satisfied and discharged. The deposited funds will be used to repay in full $145.9 million of remaining outstanding senior notes plus the related prepayment premium of $3.6 million and accrued interest of $3.5 million. As a result of these transactions, the Company recorded a loss from the extinguishment of debt of $9.0 million in the third quarter of 2012, which included $2.4 million for the write-off of unamortized deferred financing fees that related to the extinguished senior notes. Upon completion of the Company’s initial public offering, the Company recorded approximately $16.0 million of aggregate non-cash compensation expense with respect to (i) certain stock options held by its CEO that become exercisable (to the extent then vested) if following the offering, the volume-weighted average trading price of the Company’s common stock is equal to or greater than specified performance targets over a six-month period and (ii) the time vested portion of stock options containing a management call option due to the automatic termination of the call option upon completion of the offering. Upon completion of the Company’s initial public offering, the 2012 Equity Plan was adopted, and no further awards will be made under the 2007 Equity Plan. The 2012 Equity Plan provides for grants of stock options, stock appreciation rights, restricted stock and restricted stock units, performance awards and other stock-based awards determined by the compensation committee. The maximum number of shares of common stock available for issuance pursuant to the 2012 Equity Plan is initially 3,000,000 shares. As of the first business day of each fiscal year, commencing on January 1, 2013, the aggregate number of shares that may be issued pursuant to the 2012 Equity Plan will automatically increase by a number equal to 2% of the total number of shares then issued and outstanding. The 2012 Equity Plan provides that grants of performance awards will be made based upon, and subject to achieving, one or more performance measures over a performance period of not less than one year established by the compensation committee. Unless terminated earlier, the 2012 Equity Plan will terminate ten years from its effective date. On September 4, 2012, the Company entered into an amended and restated employment agreement with its CEO, Elizabeth A. Smith. The agreement became effective upon execution and extends her employment until August 13, 2017 with one year automatic renewals thereafter. In accordance with the terms of the amended and restated employment agreement, Ms. Smith’s annual base salary increased by $50,000 to $975,000, and she will be eligible for additional equity award grants beginning in 2014.

Subsequent Events

On July 25, 2012, OSI announced the commencement of a tender offer for all of its outstanding senior notes. On August 13, 2012, OSI accepted for payment $102.2 million, or 41.2%, of the aggregate principal amount of its 10% senior notes, using a portion of the net proceeds from the Company’s initial public offering. OSI paid $106.8 million for the senior notes tendered, which included $2.9 million of prepayment premium and early tender incentive fees and $1.7 million of accrued interest. Further, on August 13, 2012, the remaining senior notes were called for redemption at 102.5% of the principal amount outstanding plus accrued interest, up to but not including such date of redemption. OSI deposited the full funds for the redemption with the trustee under the indenture governing the senior notes, which was comprised of the rest of the Company’s net proceeds from its initial public offering and cash on hand, and the senior notes obligation was satisfied and discharged. The deposited funds will be used to repay in full $145.9 million of remaining outstanding senior notes plus the related prepayment premium of $3.6 million and accrued interest of $3.5 million. As a result of these transactions, the Company recorded a loss from the extinguishment of debt of $9.0 million in the third quarter of 2012, which included $2.4 million for the write-off of unamortized deferred financing fees that related to the extinguished senior notes.

Upon completion of the Company’s initial public offering, the Company recorded approximately $16.0 million of aggregate non-cash compensation expense with respect to (i) certain stock options held by its CEO that become exercisable (to the extent then vested) if following the offering, the volume-weighted average trading price of the Company’s common stock is equal to or greater than specified performance targets over a six-month period and (ii) the time vested portion of stock options containing a management call option due to the automatic termination of the call option upon completion of the offering.

Upon completion of the Company’s initial public offering, the 2012 Equity Plan was adopted, and no further awards will be made under the 2007 Equity Plan. The 2012 Equity Plan provides for grants of stock options, stock appreciation rights, restricted stock and restricted stock units, performance awards and other stock-based awards determined by the compensation committee. The maximum number of shares of common stock available for issuance pursuant to the 2012 Equity Plan is initially 3,000,000 shares. As of the first business day of each fiscal year, commencing on January 1, 2013, the aggregate number of shares that may be issued pursuant to the 2012 Equity Plan will automatically increase by a number equal to 2% of the total number of shares then issued and outstanding. The 2012 Equity Plan provides that grants of performance awards will be made based upon, and subject to achieving, one or more performance measures over a performance period of not less than one year established by the compensation committee. Unless terminated earlier, the 2012 Equity Plan will terminate ten years from its effective date.

On September 4, 2012, the Company entered into an amended and restated employment agreement with its CEO, Elizabeth A. Smith. The agreement became effective upon execution and extends her employment until August 13, 2017 with one year automatic renewals thereafter. In accordance with the terms of the amended and restated employment agreement, Ms. Smith’s annual base salary increased by $50,000 to $975,000, and she will be eligible for additional equity award grants beginning in 2014.