Stockholders' Equity - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended		1 Months Ended	9 Months Ended				6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Oct. 31, 2013 Subsequent Event [Member]	Sep. 30, 2013 Common Stock [Member]	Sep. 30, 2013 Installment 1 FY 2013 [Member]	Sep. 30, 2013 Installment 2 FY 2013 [Member]	Sep. 30, 2013 Installment 3 FY 2013 [Member]	Jun. 30, 2013 Installment 1 FY 2012 [Member]	Dec. 31, 2012 Installment 1 FY 2012 [Member]	Jun. 30, 2013 Installment 2 FY 2012 [Member]	Dec. 31, 2012 Installment 2 FY 2012 [Member]	Jun. 30, 2013 Installment 3 FY 2012 [Member]	Dec. 31, 2012 Installment 3 FY 2012 [Member]	Jun. 30, 2013 Installment 4 FY 2012 [Member]	Dec. 31, 2012 Installment 4 FY 2012 [Member]	Jun. 14, 2012 Maximum [Member]	Jun. 14, 2012 Minimum [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Common stock, shares authorized	37,000,000	37,000,000														100,000,000	37,000,000
Preferred stock, shares authorized	3,000,000	3,000,000														5,000,000	3,000,000
Repurchase of common stock	$ 3.5			$ 10.0
Cash dividend on common stock per share			$ 0.03
Payment Date				Dec. 04, 2013	Apr. 03, 2013	Jun. 05, 2013	Sep. 04, 2013		Apr. 03, 2012		Jun. 04, 2012		Aug. 31, 2012		Dec. 04, 2012
Record Date				Nov. 20, 2013	Mar. 20, 2013	May 22, 2013	Aug. 21, 2013		Mar. 20, 2012		May 18, 2012		Aug. 17, 2012		Nov. 20, 2012
Dividends payment	$ 0.5
Date of declaration of quarterly dividend cash payments					Mar. 01, 2011	Mar. 01, 2011	Mar. 01, 2011	Mar. 01, 2011		Mar. 01, 2011		Mar. 01, 2011		Mar. 01, 2011