Indebtedness - Debt Outstanding (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Notes Payable to Banks \| 2.0% Bank Debt
Debt Instrument [Line Items]
Bank debt percentage	2.00%	2.00%
Senior Subordinated Notes \| 8.00% Notes Due 2019
Debt Instrument [Line Items]
Interest rate on senior subordinated notes	8.00%	8.00%
Discount on Senior Subordinated notes	9,484
Senior Subordinated Notes \| 6.75% Notes Due 2020
Debt Instrument [Line Items]
Interest rate on senior subordinated notes	6.75%	6.75%
Senior Subordinated Notes \| 5.75% Notes Due 2021
Debt Instrument [Line Items]
Interest rate on senior subordinated notes	5.75%	5.75%
Senior Subordinated Notes \| 5.00% Notes Due 2022
Debt Instrument [Line Items]
Interest rate on senior subordinated notes	5.00%	5.00%
Senior Subordinated Notes \| 5.00% Notes Due 2023
Debt Instrument [Line Items]
Interest rate on senior subordinated notes	5.00%	5.00%

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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- Definition

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

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

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