Benefit Plans	12 Months Ended
Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Pension and Other Postretirement Benefits Disclosure	Benefit Plans: Sterling maintains an employee savings plan under Section 401(k) of the Internal Revenue Code. Substantially all employees are eligible to participate in the plan subject to certain requirements. Under the plan, employees may elect to contribute up to 10% of their salary, and Sterling will make a matching contribution equal to 35% of the employee's contribution. Each employee may make a supplemental contribution of an additional 65% of their salary. All employee contributions vest immediately and, if applicable, employer contributions vest over the employee's first three years of employment. Employees have the option of investing their contributions among selected mutual funds and Sterling common stock. Sterling contributed $3.3 million during 2013, $2.9 million during 2012 and $2.8 million during 2011 to the employee savings plan. Sterling sponsors supplemental executive retirement plans ("SERPs"). Sterling maintains and administers additional SERPs from past acquisitions. The SERPs are nonqualified, unfunded plans that are designed to provide retirement benefits for certain current and former key employees. All amounts and benefits were established and accrued at acquisition either by previous service or change of control clauses. Sterling continues to administer these benefit plans, as necessary. Sterling had recognized $1.1 million, $1.2 million, and $1.1 million for the years ended December 31, 2013, 2012 and 2011 in expenses related to the SERPs. As of December 31, 2013 and 2012, Sterling had $21.4 million and $19.6 million, respectively accrued for the SERPs. In 2006, Sterling adopted a nonqualified deferred compensation plan (the "2006 DCP") which is primarily funded through employee deferral contributions. The 2006 DCP is designed to retain and attract key employees while serving as a vehicle to assist participants in deferring current compensation to a time when taxes may be at a more personally beneficial rate and aid in saving for long-term financial needs. Participation in the 2006 DCP is limited to Directors and a select group of management or highly compensated employees as determined by the plan Committee. No employer contributions have been made to the 2006 DCP. Sterling had $202,000, $172,000, and $94,000 of net expenses related to the 2006 DCP for the years ended December 31, 2013, 2012 and 2011, respectively. As of December 31, 2013 and 2012, Sterling had an accrued liability for the 2006 DCP of $4.4 million and $4.3 million, respectively. During 2011, Sterling initiated an Employee Stock Purchase Plan ("ESPP"). Employees are eligible to participate in the ESPP, with share purchases discounted from 0% - 15% from the closing price of Sterling's common stock on the last day of the semiannual offering period. The applicable discount for 2013 and 2012 was 15%. During 2013 and 2012, 36,188 shares and 38,926 shares, respectively were issued under the plan, leaving 1,924,886 shares available for future purchase as of December 31, 2013.

Benefit Plans:

Sterling maintains an employee savings plan under Section 401(k) of the Internal Revenue Code. Substantially all employees are eligible to participate in the plan subject to certain requirements. Under the plan, employees may elect to contribute up to 10% of their salary, and Sterling will make a matching contribution equal to 35% of the employee's contribution. Each employee may make a supplemental contribution of an additional 65% of their salary. All employee contributions vest immediately and, if applicable, employer contributions vest over the employee's first three years of employment. Employees have the option of investing their contributions among selected mutual funds and Sterling common stock. Sterling contributed $3.3 million during 2013, $2.9 million during 2012 and $2.8 million during 2011 to the employee savings plan.

Sterling sponsors supplemental executive retirement plans ("SERPs"). Sterling maintains and administers additional SERPs from past acquisitions. The SERPs are nonqualified, unfunded plans that are designed to provide retirement benefits for certain current and former key employees. All amounts and benefits were established and accrued at acquisition either by previous service or change of control clauses. Sterling continues to administer these benefit plans, as necessary. Sterling had recognized $1.1 million, $1.2 million, and $1.1 million for the years ended December 31, 2013, 2012 and 2011 in expenses related to the SERPs. As of December 31, 2013 and 2012, Sterling had $21.4 million and $19.6 million, respectively accrued for the SERPs.

In 2006, Sterling adopted a nonqualified deferred compensation plan (the "2006 DCP") which is primarily funded through employee deferral contributions. The 2006 DCP is designed to retain and attract key employees while serving as a vehicle to assist participants in deferring current compensation to a time when taxes may be at a more personally beneficial rate and aid in saving for long-term financial needs. Participation in the 2006 DCP is limited to Directors and a select group of management or highly compensated employees as determined by the plan Committee. No employer contributions have been made to the 2006 DCP. Sterling had $202,000, $172,000, and $94,000 of net expenses related to the 2006 DCP for the years ended December 31, 2013, 2012 and 2011, respectively. As of December 31, 2013 and 2012, Sterling had an accrued liability for the 2006 DCP of $4.4 million and $4.3 million, respectively.

During 2011, Sterling initiated an Employee Stock Purchase Plan ("ESPP"). Employees are eligible to participate in the ESPP, with share purchases discounted from 0% - 15% from the closing price of Sterling's common stock on the last day of the semiannual offering period. The applicable discount for 2013 and 2012 was 15%. During 2013 and 2012, 36,188 shares and 38,926 shares, respectively were issued under the plan, leaving 1,924,886 shares available for future purchase as of December 31, 2013.