Dividend Restriction, Maximum Amount Per Share

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As a total of the principal notes amount, the percentage for which the notes were issued.

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Number of operating locations related to mortgage financing.

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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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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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Fair value amount of debt instrument that was repurchased.

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Weighted average interest rate of debt outstanding.

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The cash outflow from the repayment of long-term borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets before its maturity.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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Long-Term Debt - Notes Narrative (Details)				6 Months Ended
Long-Term Debt - Notes Narrative (Details)	Mar. 10, 2017 USD ($)	Sep. 30, 2016 USD ($)	May 09, 2013 USD ($)	Jun. 30, 2018 USD ($) Location $ / shares
Mortgage notes
Debt Instrument [Line Items]
Mortgage financing aggregate				$ 21,100,000
Number of operating locations related to mortgage financing \| Location				3
Debt weighted average interest rate on note				4.53%
Outstanding principal balance				$ 422,600,000
5.0% Notes
Debt Instrument [Line Items]
Stated interest rate on debt agreement			5.00%	5.00%
Principal amount			$ 300,000,000
Notes issued, percent of principal			100.00%
Outstanding notes repurchased amount		$ 10,700,000
Repurchase amount paid in cash, plus accrued and unpaid interest related thereto		$ 10,600,000
Maximum dividend (usd per share) \| $ / shares				$ 0.10
6.125% Notes
Debt Instrument [Line Items]
Stated interest rate on debt agreement	6.125%			6.125%
Principal amount	$ 250,000,000
Notes issued, percent of principal	100.00%
Maximum dividend (usd per share) \| $ / shares				$ 0.12
7.0% Senior Subordinate Notes
Debt Instrument [Line Items]
Stated interest rate on debt agreement				7.00%