Key Assumptions as Part of Black-Scholes Option Pricing Model (Detail)	3 Months Ended
	Mar. 31, 2012
Employee Stock Option
Expected term (in years)	6 years
Risk-free interest rate	1.24%
Dividend yield	1.33%
Expected volatility	59.90%
SARs
Expected term (in years)	6 years
Risk-free interest rate	1.24%
Dividend yield	1.33%
Expected volatility	59.90%