Summary of Derivatives and Fair Values (Detail) (Series F Agreement, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Oct. 31, 2008
Series F Agreement
Derivative [Line Items]
Notional Amount	$ 50,000	[1]			$ 50,000
Strike	5.2175%	[1]
Trade Date	Oct. 01, 2008	[1]
Maturity Date	Oct. 01, 2013	[1]
Fair Value of Derivative Liabilities			$ (826)	[1]

[1] Fair value excludes quarterly settlement payment due on Series F Agreement. As of December 31, 2012, the outstanding payable was $305.