Income Taxes	3 Months Ended
Mar. 31, 2013
Income Tax Expense (Benefit) [Abstract]
Income Taxes	Income Taxes: During the three months ended March 31, 2013, Sterling recognized income tax expense of $9.9 million, reflecting a 30% effective tax rate, while no income tax expense was recognized in the comparable 2012 period. The effective tax rate for the three months ended March 31, 2013 reflected permanent differences between book income and tax income, from the Borrego acquisition bargain purchase gain, in addition to tax exempt municipal bond and BOLI income. As of March 31, 2013, the net deferred tax asset was $288.8 million, including $267.9 million of net operating loss and tax credit carry-forwards, compared with $292.1 million as of December 31, 2012, including $274.0 million of net operating loss and tax credit carry-forwards. With regard to the deferred tax asset, the benefits of Sterling’s accumulated tax losses would be reduced in the event of an “ownership change,” as determined under Section 382 of the Internal Revenue Code. During 2010, in order to preserve the benefits of these tax losses, Sterling’s shareholders approved a protective amendment to the restated articles of incorporation and Sterling’s board adopted a tax preservation rights plan, both of which restrict certain stock transfers that would result in an investor acquiring more than 4.95% of Sterling’s total outstanding common stock.

Income Taxes

3 Months Ended

Mar. 31, 2013

Income Tax Expense (Benefit) [Abstract]

Income Taxes:

During the three months ended March 31, 2013, Sterling recognized income tax expense of $9.9 million, reflecting a 30% effective tax rate, while no income tax expense was recognized in the comparable 2012 period. The effective tax rate for the three months ended March 31, 2013 reflected permanent differences between book income and tax income, from the Borrego acquisition bargain purchase gain, in addition to tax exempt municipal bond and BOLI income. As of March 31, 2013, the net deferred tax asset was $288.8 million, including $267.9 million of net operating loss and tax credit carry-forwards, compared with $292.1 million as of December 31, 2012, including $274.0 million of net operating loss and tax credit carry-forwards.

With regard to the deferred tax asset, the benefits of Sterling’s accumulated tax losses would be reduced in the event of an “ownership change,” as determined under Section 382 of the Internal Revenue Code. During 2010, in order to preserve the benefits of these tax losses, Sterling’s shareholders approved a protective amendment to the restated articles of incorporation and Sterling’s board adopted a tax preservation rights plan, both of which restrict certain stock transfers that would result in an investor acquiring more than 4.95% of Sterling’s total outstanding common stock.