Schedule II - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 0	$ 0	$ 84,963
Charged to Costs and Expenses	0	0	1,570
Deductions	0	0	(86,533)
Balance at end of Period	0	0	0
Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	0	0	84,963
Charged to Costs and Expenses	0	0	1,570
Deductions	0	0	(86,533)
Balance at end of Period	$ 0	$ 0	$ 0