Financial Instruments - Summary of Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
USD Interest Rate Swap Contract One [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative, Notional Amount	$ 50,000
Liabilities:
Derivative, Fixed Interest Rate	2.878%
USD Interest Rate Swap Contract Two [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative, Notional Amount	$ 50,000
Liabilities:
Derivative, Fixed Interest Rate	2.878%
Carrying Amount
Assets:
Cash and cash equivalents	$ 203,824	$ 72,819
Fair Value
Assets:
Cash and cash equivalents	203,824	72,819
Bank Borrowings [Member] \| Carrying Amount
Liabilities:
Long-term Debt, Fair Value	795,830	951,800
Bank Borrowings [Member] \| Fair Value
Liabilities:
Long-term Debt, Fair Value	$ 795,830	951,800
Senior Notes [Member] \| Four and Three Quarters Percent Senior Notes due 2025 [Member]
Liabilities:
Stated interest rate	4.75%
Senior Notes [Member] \| Three and One Quarter Percent Senior Notes due 2025 [Member]
Liabilities:
Stated interest rate	3.25%
Senior Notes [Member] \| Four and One Eighth Percent Senior Notes Due 2028 [Member]
Liabilities:
Stated interest rate	4.125%
Senior Notes [Member] \| Carrying Amount \| Four and Three Quarters Percent Senior Notes due 2025 [Member]
Liabilities:
Long-term Debt, Fair Value	$ 300,000	300,000
Senior Notes [Member] \| Carrying Amount \| Three and One Quarter Percent Senior Notes due 2025 [Member]
Liabilities:
Long-term Debt, Fair Value	729,755	744,380
Senior Notes [Member] \| Carrying Amount \| Four and One Eighth Percent Senior Notes Due 2028 [Member]
Liabilities:
Long-term Debt, Fair Value	400,000	0
Senior Notes [Member] \| Fair Value \| Four and Three Quarters Percent Senior Notes due 2025 [Member]
Liabilities:
Long-term Debt, Fair Value	308,217	284,517
Senior Notes [Member] \| Fair Value \| Three and One Quarter Percent Senior Notes due 2025 [Member]
Liabilities:
Long-term Debt, Fair Value	748,349	746,591
Senior Notes [Member] \| Fair Value \| Four and One Eighth Percent Senior Notes Due 2028 [Member]
Liabilities:
Long-term Debt, Fair Value	$ 401,848	$ 0

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

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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.

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- References

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- References

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

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