Capital leases including purchase options.

No definition available.

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- Definition

Percentage of Notes Redeemable

+ References

No definition available.

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- Definition

Percentage of underwriting discount on senior notes.

+ References

No definition available.

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- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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- Definition

Amount of capital lease obligation due within one year or the normal operating cycle, if longer.

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-Publisher FASB

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-Topic 210

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-Name Regulation S-X (SX)

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-Section 02

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- Definition

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-Subparagraph (SX 210.5-02.22)

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- Definition

Amount of minimum lease payments for capital leases.

+ References

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- Definition

Amount necessary to reduce net minimum lease payments to present value for capital leases.

+ References

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

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

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- Definition

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

+ References

+ 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

Percentage of principal amount of debt redeemed.

+ References

No definition available.

+ Details

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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- Definition

Amount of interest capitalized during the period.

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-Glossary Allowance for Funds Used during Construction

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

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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

The amount of cash or cash equivalents contributed by the entity to fund its pension plans.

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- Definition

The cash inflow from a borrowing with the highest claim on the assets of the entity in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle, if longer).

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-Glossary Financing Activities

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Note 9 - Senior Notes, Credit Facilities and Capital Leases (Details) (USD $)	12 Months Ended	3 Months Ended
	Dec. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Feb. 28, 2014	Apr. 30, 2013	Apr. 12, 2013
Note 9 - Senior Notes, Credit Facilities and Capital Leases (Details) [Line Items]
Proceeds from Issuance of Senior Long-term Debt	$ 490,000,000
Underwriting Discount on Senior Notes					2.00%hl_UnderwritingDiscountOnSeniorNotes
Line of Credit Facility, Maximum Borrowing Capacity				100,000,000
Capital Leases Including Purchase Option		21,900,000hl_CapitalLeasesIncludingPurchaseOption
Capital Lease Obligations, Current	9,491,000us-gaap_CapitalLeaseObligationsCurrent	10,289,000us-gaap_CapitalLeaseObligationsCurrent
Capital Lease Obligations, Noncurrent	13,650,000	11,590,000
Capital Lease Obligations	23,100,000us-gaap_CapitalLeaseObligations	21,667,000us-gaap_CapitalLeaseObligations
Capital Leases, Future Minimum Payments Due		22,713,000
Capital Leases, Future Minimum Payments, Interest Included in Payments		1,046,000
Senior Notes [Member]
Note 9 - Senior Notes, Credit Facilities and Capital Leases (Details) [Line Items]
Debt Instrument, Face Amount						500,000,000
Pension Contributions	6,500,000
Debt Instrument, Unamortized Discount		7,700,000			10,000,000
Debt Instrument, Interest Rate, Stated Percentage						6.875%
Interest Costs Capitalized		3,300,000	2,700,000
Interest Expense, Debt		$ 5,700,000	$ 6,300,000
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed		100.00%
Percentage of Notes Redeemable		35.00%
Debt Instrument, Redemption Price, Percentage		101.00%