Amount of the required periodic payments applied to interest of first payment.

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Amount of increase borrowing commitment available under the revolving credit facility and term loans.

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

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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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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount of the required periodic payments applied to interest.

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Amount, after accumulated amortization, of debt discount.

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Weighted average interest rate of debt outstanding.

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

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Gross amount of debt extinguished.

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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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Average amount borrowed under the credit facility during the period.

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Amount of the fee for available but unused credit capacity under the credit facility.

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The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

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Date the credit facility terminates, in CCYY-MM-DD format.

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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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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Long-Term Debt (Details) - USD ($) $ in Thousands			12 Months Ended
Long-Term Debt (Details) - USD ($) $ in Thousands	Feb. 20, 2018	Sep. 13, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 25, 2017
Long-term Debt [Abstract]
Senior Notes outstanding			$ 1,417,392	$ 995,848
Total debt outstanding, Fair value			1,411,628	984,017
Long-term debt			1,410,188	992,406
Senior Notes Due March 1, 2028 [Member]
Long-term Debt [Abstract]
Long term debt, face amount			500,000
Periodic payment, interest			10,500
Periodic payment, interest, exception of first payment			11,608
Cash proceeds received			495,019
Original issue discount			705
Debt issuance costs			4,276
Senior Notes outstanding			$ 500,000	0
Debt instrument, interest rate, stated percentage			4.20%
Maturity Date			Mar. 01, 2028
Senior Notes Series A Due February 27, 2020 [Member]
Long-term Debt [Abstract]
Long term debt, face amount			$ 150,000
Senior Notes outstanding			$ 150,000	150,000
Debt instrument, interest rate, stated percentage			2.72%
Maturity Date			Feb. 27, 2020
Senior Notes Series B Due February 27, 2023 [Member]
Long-term Debt [Abstract]
Long term debt, face amount			$ 350,000
Senior Notes outstanding			$ 350,000	$ 350,000
Debt instrument, interest rate, stated percentage			3.29%
Maturity Date			Feb. 27, 2023
Term Loan Due September 15, 2032 [Member] \| Stewart & Stevenson LLC [Member]
Long-term Debt [Abstract]
Term debt assumed, paid off		$ 12,135
Revolving Credit Facility [Member]
Long-term Debt [Abstract]
Maximum borrowing capacity			$ 850,000
Credit facility, expiration date			Jun. 26, 2022
Line of credit, increase in aggregate commitments			$ 300,000
Commitment amount			$ 25,000
Commitment fee	0.10%		0.15%
Credit facility, amount outstanding			$ 417,373
Average borrowing under revolving credit facility			$ 411,613
Weighted average interest rate			3.10%
Revolving Credit Facility [Member] \| Stewart & Stevenson LLC [Member]
Long-term Debt [Abstract]
Maximum borrowing capacity			$ 850,000		$ 550,000
Credit facility, expiration date			Jun. 26, 2022
Revolving Credit Facility [Member] \| LIBOR [Member]
Long-term Debt [Abstract]
Basis spread on variable rate	1.00%		1.125%
Revolving Credit Facility [Member] \| Alternate Base Rate [Member]
Long-term Debt [Abstract]
Basis spread on variable rate			0.125%
Letter of Credit [Member]
Long-term Debt [Abstract]
Credit facility, amount outstanding			$ 6,788
Senior Notes [Member]
Long-term Debt [Abstract]
Long term debt, face amount			500,000
Line Of Credit [Member]
Long-term Debt [Abstract]
Maximum borrowing capacity			$ 10,000
Credit facility, expiration date			Jun. 30, 2019
Credit facility, amount outstanding			$ 1,171
Secured Debt [Member]
Long-term Debt [Abstract]
Short-term debt			$ 19,000