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Line of Credit, Long-Term Debt and Finance Lease Obligations - Summary of Estimated Fair Value of Notes (Detail) - Level 2 [Member] - Estimate of Fair Value Measurement [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
5.25% Senior Unsecured Notes Due 2023 [Member]
Debt Instrument Fair Value [Line Items]
Estimated fair value	$ 756,225	$ 766,875
6.25% Senior Unsecured Notes Due 2027 [Member]
Debt Instrument Fair Value [Line Items]
Estimated fair value	$ 1,070,000	$ 1,025,600

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- Definition

Debt Instrument Fair Value [Line Items]

+ References

No definition available.

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- Definition

Fair value portion of notes payable.

+ 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 210.5-02.19,20,22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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