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Notes Payable - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Debt Instrument [Line Items]
Collateral Account used for future payments	$ 3.1	$ 2.4
Principal and interest payments	3.1us-gaap_DebtInstrumentPeriodicPayment	2.4us-gaap_DebtInstrumentPeriodicPayment
13% Senior First Lien Notes [Member]
Debt Instrument [Line Items]
Issued aggregate principal amount	110.0
Notes maturity date	Mar. 19, 2030
Principal payments	2.3	78.9
Cash interest paid on Notes	0.1		1.5
13% Senior Second Lien Notes [Member]
Debt Instrument [Line Items]
Issued aggregate principal amount	20.0
Notes maturity date	Mar. 19, 2030
PIK Notes [Member]
Debt Instrument [Line Items]
Issued aggregate principal amount	19.4	18.5
Runoff Notes [Member]
Debt Instrument [Line Items]
Outstanding amounts of notes	$ 29.8	$ 31.2