Income Taxes	6 Months Ended
Apr. 01, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In accordance with ASC 740, Income Taxes (ASC 740), each interim period is considered integral to the annual period, and tax expense is measured using an estimated annual effective tax rate. An entity is required to record income tax expense each quarter based on its annual effective tax rate estimated for the full fiscal year and use that rate to provide for income taxes on a current year-to-date basis, adjusted for discrete taxable events that occur during the interim period. The Company’s effective tax rate for the three and six months ended April 1, 2017 was 45.6% and 43.4%, respectively, compared to 25.0% and 25.5%, respectively, for the corresponding periods in the prior year. For the current three and six month periods, the effective tax rate was higher than the statutory tax rate primarily due to the gain on the sale of the blood screening business as the tax basis of the assets sold was lower than the book basis, partially offset by the Company's excess tax benefits, earnings in jurisdictions subject to lower tax rates, the reversal of reserves from settling open audits, and the domestic production activities deduction benefit. For the three and six months ended March 26, 2016, the effective tax rate was lower than the statutory tax rate primarily due to earnings in jurisdictions subject to lower tax rates, the domestic production activities deduction benefit, and a change in the valuation allowance related to the sale of a marketable security that had a gain for book purposes. During the quarter ended April 1, 2017, the Internal Revenue Service ("IRS") completed its audit for fiscal years 2013 and 2014. The Company made a cash payment of $1.7 million and recorded an income tax benefit of $10.9 million related to the reversal of unrecognized tax benefits. The Company has $104.0 million of gross unrecognized tax benefits, excluding interest, as of April 1, 2017. The gross unrecognized tax benefits decreased $59.6 million from September 24, 2016, of which $64.0 million was a balance sheet reclassification as a result of the effective settlement during the second quarter of fiscal 2017 of uncertain tax positions related to the convertible debt exchange that took place in the second quarter of fiscal 2013 and $6.2 million was the result of the effective settlement during the quarter of other unrecognized tax benefits, which were offset by $10.6 million of other net year-to-date additions. In the next twelve months it is reasonably possible that the Company will reduce its gross unrecognized tax benefits by up to approximately $21.0 million due to expiring statutes of limitations. Non-Income Tax Matters The Company is subject to tax examinations for value added, sales-based, payroll and other non-income tax items. A number of these examinations are ongoing in various jurisdictions. The Company takes certain non-income tax positions in the jurisdictions in which it operates pursuant to ASC 450. In the normal course of business, the Company's positions and conclusions related to its non-income tax positions could be challenged, resulting in assessments by governmental authorities. In the second quarter of fiscal 2017, based on current period developments in an ongoing state tax audit, the Company determined that it was probable that it had incurred a loss related to a non-income tax issue. The Company estimated the most likely amount of loss to be $28.8 million for all open years and recorded this charge to general and administrative expenses in the second quarter of fiscal 2017. While the Company believes its estimate is reasonable and appropriate, this matter is still ongoing and additional charges could be recorded in the future.

Income Taxes

In accordance with ASC 740, Income Taxes (ASC 740), each interim period is considered integral to the annual period, and tax expense is measured using an estimated annual effective tax rate. An entity is required to record income tax expense each quarter based on its annual effective tax rate estimated for the full fiscal year and use that rate to provide for income taxes on a current year-to-date basis, adjusted for discrete taxable events that occur during the interim period.

The Company’s effective tax rate for the three and six months ended April 1, 2017 was 45.6% and 43.4%, respectively, compared to 25.0% and 25.5%, respectively, for the corresponding periods in the prior year. For the current three and six month periods, the effective tax rate was higher than the statutory tax rate primarily due to the gain on the sale of the blood screening business as the tax basis of the assets sold was lower than the book basis, partially offset by the Company's excess tax benefits, earnings in jurisdictions subject to lower tax rates, the reversal of reserves from settling open audits, and the domestic production activities deduction benefit. For the three and six months ended March 26, 2016, the effective tax rate was lower than the statutory tax rate primarily due to earnings in jurisdictions subject to lower tax rates, the domestic production activities deduction benefit, and a change in the valuation allowance related to the sale of a marketable security that had a gain for book purposes.

During the quarter ended April 1, 2017, the Internal Revenue Service ("IRS") completed its audit for fiscal years 2013 and 2014. The Company made a cash payment of $1.7 million and recorded an income tax benefit of $10.9 million related to the reversal of unrecognized tax benefits.

The Company has $104.0 million of gross unrecognized tax benefits, excluding interest, as of April 1, 2017. The gross unrecognized tax benefits decreased $59.6 million from September 24, 2016, of which $64.0 million was a balance sheet reclassification as a result of the effective settlement during the second quarter of fiscal 2017 of uncertain tax positions related to the convertible debt exchange that took place in the second quarter of fiscal 2013 and $6.2 million was the result of the effective settlement during the quarter of other unrecognized tax benefits, which were offset by $10.6 million of other net year-to-date additions.

In the next twelve months it is reasonably possible that the Company will reduce its gross unrecognized tax benefits by up to approximately $21.0 million due to expiring statutes of limitations.

Non-Income Tax Matters

The Company is subject to tax examinations for value added, sales-based, payroll and other non-income tax items. A number of these examinations are ongoing in various jurisdictions. The Company takes certain non-income tax positions in the jurisdictions in which it operates pursuant to ASC 450. In the normal course of business, the Company's positions and conclusions related to its non-income tax positions could be challenged, resulting in assessments by governmental authorities.

In the second quarter of fiscal 2017, based on current period developments in an ongoing state tax audit, the Company determined that it was probable that it had incurred a loss related to a non-income tax issue. The Company estimated the most likely amount of loss to be $28.8 million for all open years and recorded this charge to general and administrative expenses in the second quarter of fiscal 2017. While the Company believes its estimate is reasonable and appropriate, this matter is still ongoing and additional charges could be recorded in the future.