Cash Dividends (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Stockholders Equity Note [Line Items]
Cash dividends paid, date	Mar. 30, 2012	Mar. 30, 2011
Cash dividends paid, per share	$ 0.05	$ 0.05
Cash dividends paid	$ 7,788	$ 7,708