Income Taxes	6 Months Ended
Jun. 30, 2013
Income Tax Expense (Benefit) [Abstract]
Income Taxes	Income Taxes: During the three months ended June 30, 2013, Sterling recognized income tax expense of $13.0 million, reflecting a 32% effective tax rate, and during the six months ended June 30, 2013, income tax expense of $22.8 million, reflecting a 31% effective tax rate. The comparable 2012 periods included an income tax benefit of $288.8 million, the result of reversing substantially all of Sterling's deferred tax asset valuation allowance. The effective tax rate for the 2013 periods reflect permanent differences between book income and tax income from the Borrego acquisition bargain purchase gain, as well as tax exempt municipal bond and BOLI income. As of June 30, 2013, the net deferred tax asset was $290.4 million, including $260.2 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 becoming an owner of 5% or more of Sterling’s total outstanding common stock. The protective amendment and the rights plan are expected to expire on August 27, 2013.

Income Taxes

6 Months Ended

Jun. 30, 2013

Income Tax Expense (Benefit) [Abstract]

Income Taxes:

During the three months ended June 30, 2013, Sterling recognized income tax expense of $13.0 million, reflecting a 32% effective tax rate, and during the six months ended June 30, 2013, income tax expense of $22.8 million, reflecting a 31% effective tax rate. The comparable 2012 periods included an income tax benefit of $288.8 million, the result of reversing substantially all of Sterling's deferred tax asset valuation allowance. The effective tax rate for the 2013 periods reflect permanent differences between book income and tax income from the Borrego acquisition bargain purchase gain, as well as tax exempt municipal bond and BOLI income. As of June 30, 2013, the net deferred tax asset was $290.4 million, including $260.2 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 becoming an owner of 5% or more of Sterling’s total outstanding common stock. The protective amendment and the rights plan are expected to expire on August 27, 2013.