Debt Instrument Business Days

No definition available.

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- Definition

Line Of Credit Facility Fronting Fee Percentage

+ References

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

The price per share of the conversion feature embedded in the debt instrument.

+ References

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Period Type:	instant

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

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- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

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- Definition

Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

+ Details

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- Definition

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

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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

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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.

+ Details

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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- Definition

Amount, after accumulated amortization, of debt issuance costs related to line of credit arrangements. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Period Type:	instant

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- 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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Balance Type:	credit
Period Type:	instant

- 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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Period Type:	instant

- 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.

+ Details

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- Definition

The excess of the (1) fair value of consideration transferred to the holders of a security in excess of (2) the carrying amount of the security reported on the registrant's balance sheet, which will be deducted from net earnings to derive net earnings available to common shareholders. This amount is generally an adjustment considered in the computation of earnings per share.

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

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- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Debt - Additional Information (Details)			1 Months Ended	12 Months Ended
Debt - Additional Information (Details)	Nov. 15, 2018 USD ($)	Aug. 20, 2018 USD ($) $ / shares	Nov. 30, 2018 USD ($)	Dec. 31, 2020 USD ($) trading_day business_day segment $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($)	Jun. 26, 2015 USD ($)
Debt Instrument [Line Items]
Conversion price (in dollars per share) \| $ / shares				$ 101.38	$ 101.38
Loss on early extinguishment of debt				$ 0	$ 0	$ 9,072,000
Unamortized debt issue costs				3,809,000	5,248,000
Line of Credit
Debt Instrument [Line Items]
Borrowing limit used				$ 1,100,000
Convertible Note Due 2023 \| Senior Notes
Debt Instrument [Line Items]
Principal amount		$ 316,300,000
Interest rate (as a percent)		2.00%		2.00%
Conversion rate		0.0098643
Conversion price (in dollars per share) \| $ / shares		$ 101.38
Convertible Note Due 2023 \| Debt Instrument, Redemption, Period One \| Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Trading Days \| trading_day				20
Consecutive trading days \| trading_day				30
Redemption price percentage				130.00%
Convertible Note Due 2023 \| Debt Instrument, Redemption, Period Two \| Senior Notes
Debt Instrument [Line Items]
Consecutive trading days \| segment				5
Debt instrument business days \| business_day				5
Redemption price percentage				98.00%
6% senior notes due 2022 \| Senior Notes
Debt Instrument [Line Items]
Principal amount	$ 300,000,000.0
Interest rate (as a percent)	6.00%
Loss on early extinguishment of debt	$ 9,100,000
Redemption premium	6,000,000.0
Write off of deferred debt issuance cost	$ 3,100,000
Credit facility \| Line of Credit
Debt Instrument [Line Items]
Senior secured revolving line of credit							$ 550,000,000.0
Debt issuance costs			$ 1,700,000
Borrowings outstanding				$ 0	0
Unamortized debt issue costs				$ 1,300,000	$ 2,000,000.0
Credit facility \| Line of Credit \| Minimum
Debt Instrument [Line Items]
Commitment fee (as a percent)				0.20%
Fronting fees (as a percent)				1.25%
Credit facility \| Line of Credit \| Minimum \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread (as a percent)			1.25%
Credit facility \| Line of Credit \| Minimum \| Base Rate
Debt Instrument [Line Items]
Basis spread (as a percent)			0.25%
Credit facility \| Line of Credit \| Maximum
Debt Instrument [Line Items]
Commitment fee (as a percent)				0.35%
Fronting fees (as a percent)				2.00%
Credit facility \| Line of Credit \| Maximum \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread (as a percent)			2.00%
Credit facility \| Line of Credit \| Maximum \| Base Rate
Debt Instrument [Line Items]
Basis spread (as a percent)			1.00%