Retirement Plans	12 Months Ended
Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Retirement Plans	Retirement Plans The Company has five defined contribution retirement plans covering substantially all salaried employees and nonunion hourly employees. On January 1, 2015, the Simpson Manufacturing Co., Inc. 401(k) Profit Sharing Plan for Salaried Employees was amended, restated and superseded by the Simpson Manufacturing Co., Inc. 401(k) Profit Sharing Plan (the “Restated Plan”), and the Simpson Manufacturing Co., Inc. 401(k) Profit Sharing Plan for Hourly Employees was merged with and incorporated into the Restated Plan. The Restated Plan, covering United States employees, provides for quarterly contributions, limited to 3% of the employees quarterly eligible compensation, that does not require Board approval and for annual contributions in amounts that the Board authorizes, subject to certain limitations, but in no event are total contributions more than the amounts permitted under the Internal Revenue Code as deductible expense. The other four plans, covering the Company’s European and Canadian employees, require the Company to make contributions ranging from 3% to 15% of the employees’ compensation. The total cost for these retirement plans for the years ended December 31, 2015, 2014 and 2013, was $9.5 million, $8.0 million and $8.2 million, respectively. The Company also contributes to various industry-wide, union-sponsored pension funds for hourly employees who are union members and a statutorily required pension fund for employees in Switzerland. Payments to these funds aggregated $2.5 million, $2.3 million and $2.2 million for the years ended December 31, 2015, 2014 and 2013, respectively. Settlement of Pension Withdrawal Liability Under the Company's collective bargaining arrangement with the tool and die craftsman and maintenance union, the Company has been contributing to a defined-benefit pension plan. In 2014, the Company and the union formally notified the defined-benefit pension plan administrator of their intent to withdraw from the plan. In the third quarter of 2014, the plan administrator responded by issuing a demand letter informing the Company that the annual withdrawal liability payment to be made by the Company was $145,400 and the payments were to be made in perpetuity. Due to the amount and duration of payments, the Company was required to calculate and record a pension expense and liability based on the annual payments in perpetuity. At December 31, 2014, the Company discounted the payment estimate using a discount rate of 4.5%, which approximates the credit-adjusted risk-free rate for the Company and recorded a long-term liability of $3.3 million with a corresponding defined-benefit expense in cost of sales. On a quarterly basis, the Company re-evaluated the number of years that payments are required and the discount rate used to calculate the long-term liability and adjusted it as facts and circumstances changed. All adjustments to the long-term liability were charged to cost of sales in the Consolidated Statements of Operations. Because of the funding status of the plan, the annual withdrawal liability payments were recorded as interest expense on the long-term liability. In September of 2015, the defined-benefit pension plan trustees and the Company agreed to settle this long-term pension withdrawal liability, which at the time had a $3.0 million balance, for $2.0 million. As a result of the settlement, the Company reduced the long-term pension withdrawal liability by $1.0 million with a corresponding defined benefit expense reduction in cost of sales. The $2.0 million long-term pension withdrawal liability was fully paid as of September 30, 2015.

Retirement Plans

The Company has five defined contribution retirement plans covering substantially all salaried employees and nonunion hourly employees. On January 1, 2015, the Simpson Manufacturing Co., Inc. 401(k) Profit Sharing Plan for Salaried Employees was amended, restated and superseded by the Simpson Manufacturing Co., Inc. 401(k) Profit Sharing Plan (the “Restated Plan”), and the Simpson Manufacturing Co., Inc. 401(k) Profit Sharing Plan for Hourly Employees was merged with and incorporated into the Restated Plan. The Restated Plan, covering United States employees, provides for quarterly contributions, limited to 3% of the employees quarterly eligible compensation, that does not require Board approval and for annual contributions in amounts that the Board authorizes, subject to certain limitations, but in no event are total contributions more than the amounts permitted under the Internal Revenue Code as deductible expense. The other four plans, covering the Company’s European and Canadian employees, require the Company to make contributions ranging from 3% to 15% of the employees’ compensation. The total cost for these retirement plans for the years ended December 31, 2015, 2014 and 2013, was $9.5 million, $8.0 million and $8.2 million, respectively.

The Company also contributes to various industry-wide, union-sponsored pension funds for hourly employees who are union members and a statutorily required pension fund for employees in Switzerland. Payments to these funds aggregated $2.5 million, $2.3 million and $2.2 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Settlement of Pension Withdrawal Liability

Under the Company's collective bargaining arrangement with the tool and die craftsman and maintenance union, the Company has been contributing to a defined-benefit pension plan. In 2014, the Company and the union formally notified the defined-benefit pension plan administrator of their intent to withdraw from the plan. In the third quarter of 2014, the plan administrator responded by issuing a demand letter informing the Company that the annual withdrawal liability payment to be made by the Company was $145,400 and the payments were to be made in perpetuity.

Due to the amount and duration of payments, the Company was required to calculate and record a pension expense and liability based on the annual payments in perpetuity. At December 31, 2014, the Company discounted the payment estimate using a discount rate of 4.5%, which approximates the credit-adjusted risk-free rate for the Company and recorded a long-term liability of $3.3 million with a corresponding defined-benefit expense in cost of sales. On a quarterly basis, the Company re-evaluated the number of years that payments are required and the discount rate used to calculate the long-term liability and adjusted it as facts and circumstances changed. All adjustments to the long-term liability were charged to cost of sales in the Consolidated Statements of Operations. Because of the funding status of the plan, the annual withdrawal liability payments were recorded as interest expense on the long-term liability.

In September of 2015, the defined-benefit pension plan trustees and the Company agreed to settle this long-term pension withdrawal liability, which at the time had a $3.0 million balance, for $2.0 million. As a result of the settlement, the Company reduced the long-term pension withdrawal liability by $1.0 million with a corresponding defined benefit expense reduction in cost of sales. The $2.0 million long-term pension withdrawal liability was fully paid as of September 30, 2015.