(Issuance of Debt Narrative) (Details)  | 
6 Months Ended | 
|---|---|
| 
 Jun. 30, 2021  
USD ($) 
 | |
| Debt Instrument [Line Items] | |
| Cash available for general corporate purposes | $ 417,300,000 | 
| 3.75% Senior Secured Notes Due 2028 [Member] | |
| Debt Instrument [Line Items] | |
| Face amount | $ 500,000,000 | 
| Interest rate, stated percentage | 3.75% | 
| Fees paid from proceeds of debt issuance and amendment of senior secured credit facility | $ 7,700,000 | 
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- Definition Represents the remaining cash available from the proceeds of the issuance of debt after paying down existing debt, redemption premium and accrued interest and fees. No definition available. 
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- Definition Face (par) amount of debt instrument at time of issuance. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition 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. No definition available. 
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- Definition Expenses paid for obtaining loans which includes expenses such as application and origination fees. No definition available. 
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- Details 
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