Debt - Debt additional information (Detail)	9 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Senior Notes [Member]
Line of Credit Facility [Line Items]
Interest Rate Percentage	8.50%	8.50%
Debt Instrument, Maturity Date	Jun. 01, 2022
Six Percent Tangible Equity Units [Member]
Line of Credit Facility [Line Items]
Average interest rate	6.00%	6.00%
Debt Instrument, Maturity Date	Dec. 15, 2016
Secured Debt [Member]
Line of Credit Facility [Line Items]
Average interest rate	3.19%	3.17%
Other indebtedness [Member]
Line of Credit Facility [Line Items]
Variable and fixed interest rates ranging, minimum	2.25%
Variable and fixed interest rates ranging, maximum	5.50%
Convertible Debt [Member]
Line of Credit Facility [Line Items]
Interest Rate Percentage	3.75%	3.75%
Debt Instrument, Maturity Date	Mar. 01, 2020

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

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 210.5-02.22(a)(1))

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

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	instant

- Definition

Maximum contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Definition

Minimum contractual interest rate for funds borrowed, under the debt agreement.

+ 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 210.5-02.22(a)(2))

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

+ Details

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Namespace Prefix:	us-gaap_
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Period Type:	duration

- Definition

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

+ 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 210.5-02.22(a)(2))

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

+ 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

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ 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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