Income Taxes	6 Months Ended
Jun. 30, 2012
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rates for the three months ended June 30, 2012 and 2011 were 42.1% and 38.4%, respectively. The effective tax rates for the six months ended June 30, 2012 and 2011 were 56.5% and 38.6%, respectively. These rates differed from the federal statutory rate due primarily to state taxes which were partially offset by the California R&D tax credit. As of December 31, 2011, the Company had $28.1 million of gross unrecognized tax benefits. During the six months ended June 30, 2012, the Company had an increase in gross unrecognized tax benefits of approximately $1.4 million. The gross unrecognized tax benefits, if recognized by the Company, will result in a reduction of approximately $23.3 million to the provision for income taxes thereby favorably impacting the Company’s effective tax rate. The Company’s unrecognized tax benefits are classified as “Other non-current liabilities” on the Consolidated Balance Sheets. The Company includes interest and penalties related to unrecognized tax benefits within the "Provision for income taxes" on the Consolidated Statements of Operations. As of June 30, 2012, the total amount of gross interest and penalties accrued was $2.7 million, and is classified as “Other non-current liabilities” on the Consolidated Balance Sheet. Deferred tax assets include $9.0 million and $10.0 million classified as “Other current assets” and $40.1 million and $28.3 million classified as “Other non-current assets” on the Consolidated Balance Sheets as of June 30, 2012 and December 31, 2011, respectively. In evaluating its ability to realize the net deferred tax assets, the Company considered all available positive and negative evidence, including its past operating results and the forecast of future market growth, forecasted earnings, future taxable income, and prudent and feasible tax planning strategies. As of June 30, 2012 and December 31, 2011, it was considered more likely than not that substantially all deferred tax assets would be realized, and no significant valuation allowance was recorded. Income tax benefits attributable to the exercise of employee stock options of $0.3 million and $18.3 million, during the three months ended June 30, 2012 and 2011, respectively, were recorded directly to "Additional paid-in capital" on the Consolidated Balance Sheets. Income tax benefits attributable to the exercise of employee stock options of $4.1 million and $33.4 million, during the six months ended June 30, 2012 and 2011, respectively, were recorded directly to "Additional paid-in capital" on the Consolidated Balance Sheets. The Company files U.S. federal, state and foreign tax returns. The Company is currently under examination by the IRS for the years 2008 through 2010. The Company is currently under examination by the state of California for the years 2006 and 2007. The years 1997 through 2005, as well as 2008 through 2010, remain subject to examination by the state of California. Given the potential outcome of the current examinations, as well as the impact of the current examination on the potential expiration of the statute of limitations, it is reasonably possible that the balance of unrecognized tax benefits could significantly change within the next twelve months. However, at this time, an estimate of the range of reasonably possible adjustments to the balance of unrecognized tax benefits cannot be made.

Income Taxes

The effective tax rates for the three months ended June 30, 2012 and 2011 were 42.1% and 38.4%, respectively. The effective tax rates for the six months ended June 30, 2012 and 2011 were 56.5% and 38.6%, respectively. These rates differed from the federal statutory rate due primarily to state taxes which were partially offset by the California R&D tax credit. As of December 31, 2011, the Company had $28.1 million of gross unrecognized tax benefits. During the six months ended June 30, 2012, the Company had an increase in gross unrecognized tax benefits of approximately $1.4 million. The gross unrecognized tax benefits, if recognized by the Company, will result in a reduction of approximately $23.3 million to the provision for income taxes thereby favorably impacting the Company’s effective tax rate. The Company’s unrecognized tax benefits are classified as “Other non-current liabilities” on the Consolidated Balance Sheets. The Company includes interest and penalties related to unrecognized tax benefits within the "Provision for income taxes" on the Consolidated Statements of Operations. As of June 30, 2012, the total amount of gross interest and penalties accrued was $2.7 million, and is classified as “Other non-current liabilities” on the Consolidated Balance Sheet.

Deferred tax assets include $9.0 million and $10.0 million classified as “Other current assets” and $40.1 million and $28.3 million classified as “Other non-current assets” on the Consolidated Balance Sheets as of June 30, 2012 and December 31, 2011, respectively. In evaluating its ability to realize the net deferred tax assets, the Company considered all available positive and negative evidence, including its past operating results and the forecast of future market growth, forecasted earnings, future taxable income, and prudent and feasible tax planning strategies. As of June 30, 2012 and December 31, 2011, it was considered more likely than not that substantially all deferred tax assets would be realized, and no significant valuation allowance was recorded.

Income tax benefits attributable to the exercise of employee stock options of $0.3 million and $18.3 million, during the three months ended June 30, 2012 and 2011, respectively, were recorded directly to "Additional paid-in capital" on the Consolidated Balance Sheets. Income tax benefits attributable to the exercise of employee stock options of $4.1 million and $33.4 million, during the six months ended June 30, 2012 and 2011, respectively, were recorded directly to "Additional paid-in capital" on the Consolidated Balance Sheets.

The Company files U.S. federal, state and foreign tax returns. The Company is currently under examination by the IRS for the years 2008 through 2010. The Company is currently under examination by the state of California for the years 2006 and 2007. The years 1997 through 2005, as well as 2008 through 2010, remain subject to examination by the state of California. Given the potential outcome of the current examinations, as well as the impact of the current examination on the potential expiration of the statute of limitations, it is reasonably possible that the balance of unrecognized tax benefits could significantly change within the next twelve months. However, at this time, an estimate of the range of reasonably possible adjustments to the balance of unrecognized tax benefits cannot be made.