Income Taxes	6 Months Ended
Jun. 28, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company's effective tax rate for the second quarter of 2019 and 2018 was 18.8% and 20.9%, respectively, and 18.5% and 17.0% for the first six months of 2019 and 2018, respectively. The effective tax rate for each period is lower than the statutory tax rate primarily due to the impact of percentage depletion and the research and development credit. Additionally, the effective tax rate for the first six months of 2019 included a net discrete income tax benefit of $0.5 million, primarily related to excess tax benefits from stock-based compensation. The effective tax rate for the first six months of 2018 included a net discrete income tax benefit of $1.0 million, primarily related to Staff Accounting Bulletin (SAB) No. 118 adjustments.

Income Taxes

6 Months Ended

Jun. 28, 2019

The Company's effective tax rate for the second quarter of 2019 and 2018 was 18.8% and 20.9%, respectively, and 18.5% and 17.0% for the first six months of 2019 and 2018, respectively. The effective tax rate for each period is lower than the statutory tax rate primarily due to the impact of percentage depletion and the research and development credit. Additionally, the effective tax rate for the first six months of 2019 included a net discrete income tax benefit of $0.5 million, primarily related to excess tax benefits from stock-based compensation. The effective tax rate for the first six months of 2018 included a net discrete income tax benefit of $1.0 million, primarily related to Staff Accounting Bulletin (SAB) No. 118 adjustments.