Long-Term Debt - Narrative (Details) - USD ($)	9 Months Ended
Sep. 30, 2019	May 30, 2017
Revolving unsecured credit facility, maturing 2023 (1) \| Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 425,000,000.0
Amount outstanding	340,000,000.0
Letters of credit outstanding	2,800,000
Remaining borrowing capacity	$ 82,200,000
Commitment fee (as a percent)	0.50%
Interest rate at end of period (as a percent)	4.50%
Net proceeds	$ 45,000,000.0
Revolving unsecured credit facility, maturing 2023 (1) \| Line of Credit \| 30-day LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.50%
Revolving unsecured credit facility, maturing 2023 (1) \| Line of Credit \| 30-day LIBOR \| Minimum
Debt Instrument [Line Items]
Stated interest rate (as a percent)	0.00%
Revolving unsecured credit facility, maturing 2023 (1) \| Line of Credit \| Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.50%
5.375% senior unsecured notes due 2024 \| Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.375%	5.375%
Face amount		$ 300,000,000.0
Debt ratio	2.25

Debt Covenant, Total Debt Ratio Threshold

No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
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- Definition

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

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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.

+ References

No definition available.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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-Name Accounting Standards Codification
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-SubTopic 10
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- Definition

The effective interest rate at the end of the reporting period.

+ References

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

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- Definition

The net cash inflow or cash outflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with either short term or long term maturity that is collateralized (backed by pledge, mortgage or other lien in the entity's assets).

+ References

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