Stockholders' Equity - Dividend Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended		1 Months Ended	9 Months Ended		1 Months Ended	9 Months Ended		1 Months Ended	9 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Feb. 28, 2011 Installment 1 FY 2013 [Member]	Sep. 30, 2013 Installment 1 FY 2013 [Member]	Apr. 03, 2013 Installment 1 FY 2013 [Member]	Feb. 28, 2011 Installment 2 FY 2013 [Member]	Sep. 30, 2013 Installment 2 FY 2013 [Member]	Jun. 05, 2013 Installment 2 FY 2013 [Member]	Feb. 28, 2011 Installment 3 FY 2013 [Member]	Sep. 30, 2013 Installment 3 FY 2013 [Member]	Sep. 04, 2013 Installment 3 FY 2013 [Member]	Feb. 28, 2011 Installment 1 FY 2012 [Member]	Dec. 31, 2012 Installment 1 FY 2012 [Member]	Apr. 03, 2012 Installment 1 FY 2012 [Member]	Feb. 28, 2011 Installment 2 FY 2012 [Member]	Dec. 31, 2012 Installment 2 FY 2012 [Member]	Jun. 04, 2012 Installment 2 FY 2012 [Member]	Feb. 28, 2011 Installment 3 FY 2012 [Member]	Dec. 31, 2012 Installment 3 FY 2012 [Member]	Aug. 31, 2012 Installment 3 FY 2012 [Member]	Feb. 28, 2011 Installment 4 FY 2012 [Member]	Dec. 31, 2012 Installment 4 FY 2012 [Member]	Dec. 04, 2012 Installment 4 FY 2012 [Member]
Dividends Payable [Line Items]
Record Date						Mar. 20, 2013			May 22, 2013			Aug. 21, 2013			Mar. 20, 2012			May 18, 2012			Aug. 17, 2012			Nov. 20, 2012
Payment Date						Apr. 03, 2013			Jun. 05, 2013			Sep. 04, 2013			Apr. 03, 2012			Jun. 04, 2012			Aug. 31, 2012			Dec. 04, 2012
Per Share Amount	$ 0.030	$ 0.025	$ 0.090	$ 0.075	$ 0.030			$ 0.030			$ 0.030			$ 0.025			$ 0.025			$ 0.025			$ 0.025
Dividend Payment							$ 457			$ 457			$ 460			$ 381			$ 379			$ 380			$ 378