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

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Percentage of principal amount of debt redeemed.

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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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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.

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Debt (Debt Repurchases) (Details) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
Debt (Debt Repurchases) (Details) - USD ($)	Jul. 12, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt		$ 1,472,000	$ 594,000	$ 3,035,000	$ (5,147,000)
5.125% Senior Notes due 2023
Debt Instrument [Line Items]
Stated interest rate		5.125%		5.125%
5.875% Senior Notes due 2022
Debt Instrument [Line Items]
Stated interest rate		5.875%		5.875%
Amended Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 100,000.0		$ 100,000.0
Gain (loss) on extinguishment of debt	$ (1,200,000)
6.00% Senior Notes due 2026
Debt Instrument [Line Items]
Stated interest rate		6.00%		6.00%
5.875% Senior Notes due 2024
Debt Instrument [Line Items]
Stated interest rate		5.875%		5.875%
Senior Notes \| 5.125% Senior Notes due 2023
Debt Instrument [Line Items]
Stated interest rate		5.125%		5.125%		5.125%
Debt instrument, repurchased face amount		$ 11,000,000.0		$ 11,000,000.0
Percentage of principal amount redeemed				75.66%
Repurchase amount		$ 8,300,000		$ 8,300,000
Gain (loss) on extinguishment of debt				$ 3,000,000.0
Senior Notes \| 5.875% Senior Notes due 2022
Debt Instrument [Line Items]
Stated interest rate		5.875%		5.875%		5.875%
Debt instrument, repurchased face amount						$ 56,000,000.0
Percentage of principal amount redeemed						97.55%
Repurchase amount						$ 54,700,000
Gain (loss) on extinguishment of debt						$ (300,000)
Senior Notes \| 6.00% Senior Notes due 2026
Debt Instrument [Line Items]
Stated interest rate		6.00%		6.00%		6.00%
Senior Notes \| 5.875% Senior Notes due 2024
Debt Instrument [Line Items]
Stated interest rate		5.875%		5.875%		5.875%
Debt instrument, repurchased face amount		$ 2,000,000.0		$ 2,000,000.0
Percentage of principal amount redeemed		76.75%
Repurchase amount		$ 1,500,000		$ 1,500,000