Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Face (par) amount of debt instrument at time of issuance.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

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The cash inflow from a borrowing with the highest claim on the assets of the entity in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle, if longer).

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Debt - 2029 and 2049 Notes (Details) - USD ($)	12 Months Ended
Debt - 2029 and 2049 Notes (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 10,600,000	$ 0	$ 21,200,000
Payments of related issuance costs	6,500,000	$ 0	$ 11,900,000
Senior Notes
Debt Instrument [Line Items]
Proceeds from offering	693,300,000
Senior Notes \| Senior Notes Due Two Thousand Twenty Nine
Debt Instrument [Line Items]
Aggregate principal amount	$ 375,000,000.0
Stated interest rate	4.25%
Stated coupon rate	99.691%
Yield to maturity	4.288%
Long-term debt, gross	$ 375,000,000.0
Loss on extinguishment of debt	10,600,000
Payments of related issuance costs	6,500,000
Senior Notes \| Senior Notes Due Two Thousand Forty Nine
Debt Instrument [Line Items]
Aggregate principal amount	$ 325,000,000.0
Stated interest rate	5.25%
Stated coupon rate	98.32%
Yield to maturity	5.363%
Long-term debt, gross	$ 325,000,000.0
Senior Notes \| Senior Notes Due Two Thousand Twenty Four
Debt Instrument [Line Items]
Stated coupon rate	102.688%
Yield to maturity		5.375%
Long-term debt, gross	$ 325,000,000.0	$ 325,000,000.0