Debt Covenant, Debt Limit

No definition available.

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- Definition

Line Of Credit Facility Debt To Net Worth Ratio

+ References

No definition available.

+ Details

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- Definition

Line Of Credit Facility Fixed Charge Coverage Ratio

+ References

No definition available.

+ Details

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- Definition

Minimum Net Worth Amount

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Standby Letters Of Credit Contractual Amount

+ References

No definition available.

+ Details

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- Definition

Working Capital Ratio

+ References

No definition available.

+ Details

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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.

+ Details

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13476-108611

+ 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

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

+ References

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of the required periodic payments applied to interest.

+ References

+ Details

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

- Definition

Percentage of principal amount of debt redeemed.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Description of covenants that limit or prohibit certain actions or activities without the lender's prior consent within a specified period of time or until certain specified targets are achieved for example, reduction of the debt or an increase in net worth to a specified amount).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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- 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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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- 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

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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

- Definition

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(g))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(5))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Balance Type:	debit
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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Long Term Debt - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Mar. 17, 2014
Debt Instrument [Line Items]
Carrying value of Long-term Debt	$ 615,994,000	$ 631,247,000
Short-term investment limit	64,237,000	289,806,000
Letters of credit outstanding under the facility	$ 12,400,000	13,000,000
Middle East [Member]
Debt Instrument [Line Items]
Revolving credit facility, maturity date	Oct. 29, 2018
Letter of credit securing workers compensation policy	$ 9,200,000
5.25% Senior Notes due March 15, 2019 [Member]
Debt Instrument [Line Items]
Carrying value of Long-term Debt	500,000,000	500,000,000
Fair market value of Senior Notes	$ 499,200,000	474,400,000
5.25% Senior Notes due March 15, 2019 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	5.25%				5.25%
Percentage of principal amount redeemed	101.00%
Debt instrument restrictive covenants	The Notes contain restrictive covenants, including limitations on incurring indebtedness, creating liens, selling assets, and entering into certain transactions with affiliates. The covenants limit our ability to pay cash dividends on common stock, repurchase or redeem common or preferred equity, prepay subordinated debt, and make certain investments.
Debt Instrument, Maturity Date	Mar. 15, 2019
Interest Expense Fund [Member]
Debt Instrument [Line Items]
Periodic payment of debt interest	$ 30,500,000	$ 29,200,000	$ 27,700,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Increased Borrowing capacity	$ 130,000,000.0			$ 150,000,000.0
Revolving Credit facility, Covenants, consolidated working capital ratio	200.00%
Revolving Credit facility, Covenants, consolidated net worth ratio	150.00%
Revolving Credit facility, Covenants, fixed coverage ratio	100.00%			110.00%
Revolving Credit facility, Covenants, consolidated net worth	$ 500,000,000			$ 450,000,000.0
Debt Covenant, Debt Limit	5,000,000.0
Letters of credit outstanding under the facility	7,600,000
Letter of credit securing workers compensation policy	$ 3,200,000
Revolving Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
LIBOR plus interest rate on borrowed funds	2.75%
Minimum [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Short-term investment limit	$ 150,000,000.0