Notes Payable, Collateralized and Short-Term Borrowings - Carrying Amounts and Estimated Fair Values of Company's Long-Term Debt (Parenthetical) (Detail)	Dec. 31, 2013 8.75% Convertible Notes [Member]	Dec. 31, 2012 8.75% Convertible Notes [Member]	Apr. 01, 2010 8.75% Convertible Notes [Member]	Mar. 31, 2010 8.75% Convertible Notes [Member]	Dec. 31, 2013 4.50% Convertible Notes [Member]	Dec. 31, 2012 4.50% Convertible Notes [Member]	Jul. 29, 2011 4.50% Convertible Notes [Member]	Dec. 31, 2013 8.125% Senior Notes [Member]	Dec. 31, 2012 8.125% Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	8.75%	8.75%	8.75%	8.75%	4.50%	4.50%	4.50%	8.125%	8.125%

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

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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant