Earnings Per Share - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended	6 Months Ended		1 Months Ended
	May 09, 2012	Jun. 30, 2012	Jun. 30, 2012	Feb. 15, 2012	Jul. 12, 2012 Dividend Declared
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Increase in dividend rate, percentage				14.00%
Increased in dividend amount per share				$ 0.2
Declared cash dividend per share	$ 0.20				$ 0.20
Cash dividend, declared date	May 09, 2012				Jul. 12, 2012
Cash dividend, payable date	Jul. 01, 2012				Oct. 01, 2012
Cash dividend, recorded date	Jun. 15, 2012				Sep. 14, 2012
Shares repurchased, in shares		215,000	215,000
Shares repurchased		$ 13,695	$ 13,695
Shares available for repurchase		4,785,000	4,785,000