Debt (Details) € in Millions		1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 19, 2016 USD ($)	Oct. 25, 2011 USD ($)	Apr. 02, 2017	Dec. 31, 2017 USD ($)	Dec. 30, 2012 USD ($)	Dec. 31, 2017 EUR (€)	Jan. 01, 2017 USD ($)	Aug. 11, 2016 USD ($)	Jul. 19, 2016 EUR (€)	Sep. 30, 2012 USD ($)
Basis spread on variable rate			1.30%
Unamortized discount and debt issuance costs				$ (15,717,000)
Maturities of Long-term Debt [Abstract]
2017				217,385,000
2018				14,506,000
2019				9,349,000
2020				1,135,912,000
2021				6,303,000
Thereafter				638,371,000
Long-term Debt Before Unamortized Discount				2,021,826,000
Total				2,006,109,000
Other Long-term Debt, Current				217,306,000			$ 1,172,000
Line of Credit, Maturing August 11, 2021 [Member]
Unsecured revolving credit facility, amount				1,000,000,000				$ 1,000,000,000
Line of Credit Facility, Remaining Borrowing Capacity				363,600,000
Letters of credit issued and outstanding				$ 11,400,000
Interest rate terms under amended senior unsecured revolving credit facility				The interest rates under the senior unsecured revolving credit facility are based on the Eurocurrency rate or the base rate at the time of borrowing plus a margin. The base rate is the higher of (i) the rate of interest in effect for such day as publicly announced from time to time by JP Morgan Chase Bank, N.A. as its "prime rate," (ii) the Federal Funds rate plus 50 basis points or (iii) one-month Libor plus 1.00%.
Weighted average interest rates under amended senior unsecured revolving credit facility				The Eurocurrency margin as of December 31, 2017 was 110 basis points. The weighted average Eurocurrency interest rate as of December 31, 2017 was 1.56%, resulting in a weighted average effective Eurocurrency rate, including the margin, of 2.66%, which was the interest applicable to the borrowings outstanding under the Eurocurrency rate as of December 31, 2017
Aggregate borrowings under the amended facility				$ 625,000,000
Unamortized discount and debt issuance costs				(3,339,000)
Unamortized Debt Issuance Expense				3,300,000			4,300,000
Maturities of Long-term Debt [Abstract]
2017				0
2018				0
2019				0
2020				625,000,000
2021				0
Thereafter				0
Long-term Debt Before Unamortized Discount				625,000,000
Total				$ 621,661,000			0
Line of Credit, Maturing August 11, 2021 [Member] | Base Rate Option Three [Member] | Line of Credit [Member]
Basis spread on variable rate				1.00%
Line of Credit, Maturing August 11, 2021 [Member] | Eurocurrency Rate [Member]
Basis spread on variable rate				1.10%
Line of Credit, Maturing August 11, 2021 [Member] | Eurocurrency Rate [Member] | Line of Credit [Member]
Basis spread on variable rate				1.10%
Line of Credit, Maturing August 11, 2021 [Member] | Base Rate Option Two [Member] | Line of Credit [Member]
Basis spread on variable rate				0.50%
Line of Credit, Maturing December 16, 2016 [Member] | Eurocurrency Rate [Member]
Description of variable rate basis				Eurocurrency margin
Line of Credit, Maturing December 16, 2016 [Member] | Base Rate Option Two [Member]
Description of variable rate basis				Federal Funds
2021 Notes [Member]
Interest rate terms under amended senior unsecured revolving credit facility				Interest on the 2021 Notes is payable semi-annually on May 15th and November 15th each year. Prior to August 15, 2021 (three months prior to their maturity date), the Company may redeem the 2021 Notes in whole or in part, at its option, at a redemption price equal to the greater of (i) 100% of the principal amount of the 2021 Notes to be redeemed, plus accrued and unpaid interest, or (ii) the sum of the present values of the remaining scheduled payments of principal and interest in respect to the 2021 Notes being redeemed, discounted on a semi-annual basis, at the Treasury Rate plus 45 basis points, plus accrued and unpaid interest.
Unsecured senior notes, interest rate percent		5.00%
Unsecured senior notes, face value		$ 500,000,000
Gross proceeds from the issuance of debt instrument		$ 496,900,000
Senior unsecured notes issuance as percentage of principal amount		99.372%
Unamortized discount and debt issuance costs				$ (3,417,000)
Unamortized Debt Issuance Expense				2,000,000			2,500,000
Debt Instrument, Redemption Percentage Upon Change of Control and Downgrade of Debt Instrument		101.00%
Maturities of Long-term Debt [Abstract]
2017				0
2018				0
2019				0
2020				500,000,000
2021				0
Thereafter				0
Long-term Debt Before Unamortized Discount				500,000,000
Total				$ 496,583,000			495,800,000
2021 Notes [Member] | Treasury Rate [Member]
Basis spread on variable rate				0.45%
1.875 Percent Ten Year Senior Unsecured Notes [Member]
Debt Instrument, Maturity Date	Jul. 19, 2026
Unsecured senior notes, interest rate percent									1.875%
Gross proceeds from the issuance of debt instrument	$ 492,300,000
Senior unsecured notes issuance as percentage of principal amount									99.118%
Unamortized discount and debt issuance costs				$ (8,961,000)
Unamortized Debt Issuance Expense				4,300,000			4,800,000
Debt Instrument, Redemption Percentage Upon Change of Control and Downgrade of Debt Instrument	101.00%
Maturities of Long-term Debt [Abstract]
2017				0
2018				0
2019				0
2020				0
2021				0
Thereafter				600,700,000
Long-term Debt Before Unamortized Discount				600,700,000
Total				591,739,000			517,800,000
Financing Lease Obligations [Member]
Additional Financing Lease Obligations					$ 11,500,000
Unamortized discount and debt issuance costs				0
Maturities of Long-term Debt [Abstract]
2017				1,370,000
2018				1,532,000
2019				1,597,000
2020				1,664,000
2021				1,639,000
Thereafter				28,109,000
Long-term Debt Before Unamortized Discount				35,911,000
Total				35,911,000
Other Long-term Debt				35,900,000			37,100,000			$ 29,300,000
Other Long-term Debt, Current				1,400,000			1,200,000
Other Long-term Debt, Noncurrent				$ 34,500,000			$ 35,900,000
Term Loan Credit Facility, 12 Months Maturity [Member]
Debt Instrument, Maturity Date				Dec. 18, 2018
Short-term Debt, Terms				twelve months
Short-term Debt, Maximum Amount Outstanding During Period				$ 200,000,000
Interest rate terms under amended senior unsecured revolving credit facility				The interest rates under the senior unsecured term loan credit facility are based on the Eurocurrency rate or the base rate at the time of the borrowing, plus a margin. The base rate is the higher of (i) the rate of interest in effect for such day as publicly announced from time to time by JP Morgan Chase Bank, N.A. as its "prime rate," (ii) the Federal Funds rate plus 50 basis points or (iii) an adjusted one-month Libor plus 1.00%. The Eurocurrency margin as of December 31, 2017 was 110 basis points.
Weighted average interest rates under amended senior unsecured revolving credit facility				The weighted average Eurocurrency interest rate as of December 31, 2017 was 1.56%, resulting in a weighted average effective Eurocurrency rate, including the margin, of 2.66%, which was the interest applicable to the borrowings outstanding under the Eurocurrency rate as of December 31, 2017
Unamortized discount and debt issuance costs				$ 0
Term Loan Credit Facility, Maximum Borrowing Capacity				200,000,000
Maturities of Long-term Debt [Abstract]
2017				200,000,000
2018				0
2019				0
2020				0
2021				0
Thereafter				0
Long-term Debt Before Unamortized Discount				200,000,000
Total				$ 200,000,000
Term Loan Credit Facility, 12 Months Maturity [Member] | Base Rate Option Three [Member]
Basis spread on variable rate				1.00%
Term Loan Credit Facility, 12 Months Maturity [Member] | Base Rate Option Two [Member]
Basis spread on variable rate				0.50%
Other Debt Facilities - EUROIMMUN [Member]
Interest rate terms under amended senior unsecured revolving credit facility				The bank loans in the aggregate amount of $44.8 million bear fixed interest rates between 1.1% and 7.9% and bank loans in the aggregate amount of $12.4 million bear variable interest rates based on the Euribor rate plus a margin between 1.3% and 1.5%.
Unamortized discount and debt issuance costs				$ 0
Maturities of Long-term Debt [Abstract]
2017				16,015,000
2018				12,974,000
2019				7,752,000
2020				9,248,000
2021				4,664,000
Thereafter				9,562,000
Long-term Debt Before Unamortized Discount				60,215,000
Total				$ 60,215,000
Other Long-term Debt | €						€ 60.2
Long-term Debt, Percentage Bearing Fixed Interest, Amount | €						47.8
Long-term Debt, Percentage Bearing Variable Interest, Amount | €						€ 12.4
Other Debt Facilities - EUROIMMUN [Member] | Minimum [Member]
Unsecured senior notes, interest rate percent				0.10%		0.10%
Other Debt Facilities - EUROIMMUN [Member] | Maximum [Member]
Unsecured senior notes, interest rate percent				7.90%		7.90%
Other Debt Facilities - EUROIMMUN [Member] | Euribor Rate [Member] | Maximum [Member]
Basis spread on variable rate			1.50%
Other Unsecured Revolving Debt Facilities [Member]
Other Unsecured Revolving Credit Facility				$ 2,700,000
Interest rate terms under amended senior unsecured revolving credit facility				The unsecured revolving debt facilities bear fixed interest rates between 0.05% and 1.95% and will mature in 2018.
Other Unsecured Revolving Debt Facilities [Member] | Minimum [Member]
Unsecured senior notes, interest rate percent				0.05%		0.05%
Other Unsecured Revolving Debt Facilities [Member] | Maximum [Member]
Unsecured senior notes, interest rate percent				1.95%		1.95%
Other Secured Bank Loan [Member]
Interest rate terms under amended senior unsecured revolving credit facility				The secured bank loan of $0.3 million bears a fixed annual interest rate of 1.95% and is repaid in monthly installments until 2027.
Unsecured senior notes, interest rate percent				1.95%		1.95%
Maturities of Long-term Debt [Abstract]
Secured Debt | €						€ 0.3
Euro Member Countries, Euro | 1.875 Percent Ten Year Senior Unsecured Notes [Member]
Unsecured senior notes, face value | €									€ 500.0
Euro Member Countries, Euro | Other Debt Facilities - EUROIMMUN [Member]
Maturities of Long-term Debt [Abstract]
Other Long-term Debt | €						47.6
United States of America, Dollars | Other Debt Facilities - EUROIMMUN [Member]
Maturities of Long-term Debt [Abstract]
Other Long-term Debt | €						57.2
Long-term Debt, Percentage Bearing Fixed Interest, Amount | €						44.8
Secured Debt | €						15.0
Unsecured Debt | €						€ 42.2
United States of America, Dollars | Other Debt Facilities - EUROIMMUN [Member] | Minimum [Member]
Unsecured senior notes, interest rate percent				1.10%		1.10%
United States of America, Dollars | Other Debt Facilities - EUROIMMUN [Member] | Maximum [Member]
Unsecured senior notes, interest rate percent				7.90%		7.90%