Repurchase Agreement - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
	Mar. 31, 2006 Year BasisPoint	Jun. 30, 2011
Repurchase Agreement Counterparty [Line Items]
Repurchase agreement, authorized amount	$ 50
Repurchase agreement, term	5
Repurchase agreement, maturity period	March 2011
Repurchase Agreement, LIBOR rate, Basis points	100
Repurchase Agreement, LIBOR rate, interest rate	4.99%
Repurchase agreement, utilized amount		50
Repurchase agreement, Maturity Date		Mar. 21, 2011
Interest expense associated with borrowing		$ 1.8