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Debt (Narrative) (Details) - USD ($) |  | 1 Months Ended | 3 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jan. 24, 2019 | Jan. 31, 2013 | Mar. 31, 2019 | Dec. 31, 2019 | Dec. 31, 2018
Debt Instrument [Line Items] |  |  |  |  |
Carrying value of outstanding debt |  |  |  | $ 0 | $ 210,400,000
Unamortized original issue discount |  |  |  |  | 1,600,000
Current maturities of long-term debt |  |  |  | 0 | 208,805,000
Senior Subordinated Notes [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Term loan (up to) |  |  |  |  | $ 210,000,000.0
Interest rate |  |  |  |  | 6.25%
Other Debt Obligations [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Carrying value of outstanding debt |  |  |  |  | $ 2,000,000.0
Senior Subordinated 6.25% Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Carrying value of outstanding debt |  |  |  |  | 210,000,000
Interest rate |  | 6.25% |  |  |
Notes issued |  | $ 210,000,000 |  |  |
Write off of deferred debt issuance cost |  |  | $ 1,100,000 |  |
Revolving Credit Facility | 2019 Senior Credit Agreement [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Current borrowing capacity | $ 400,000,000 |  |  |  |
Maximum borrowing capacity under the revolving credit facility | $ 700,000,000 |  |  |  |
Revolving Credit Facility | 2019 Senior Credit Agreement [Member] | Minimum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Annual commitment fee | 0.15% |  |  |  |
Revolving Credit Facility | 2019 Senior Credit Agreement [Member] | Minimum | LIBOR |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
LIBOR floor, plus | 1.125% |  |  |  |
Revolving Credit Facility | 2019 Senior Credit Agreement [Member] | Maximum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Annual commitment fee | 0.25% |  |  |  |
Revolving Credit Facility | 2019 Senior Credit Agreement [Member] | Maximum | LIBOR |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
LIBOR floor, plus | 2.00% |  |  |  |
Term Loan | 2019 Senior Credit Agreement [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Term loan (up to) | $ 300,000,000 |  |  |  |
Standby Letters of Credit | Senior Credit Agreement |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Maximum borrowing capacity under the revolving credit facility |  |  |  | 6,000,000.0 |
Revolving Credit Facility | Senior Credit Agreement |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Availability amount |  |  |  | $ 394,000,000.0 | $ 290,800,000

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