Line of Credit - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Line of Credit Facility [Line Items]
Available line of credit	$ 30.0
Line of credit, variable rate basis	LIBOR plus
Line of credit, expiration date	Mar. 31, 2015
Minimum cash balance required to maintain under the credit agreement	$ 25
LIBOR | Minimum
Line of Credit Facility [Line Items]
Line of credit basis spread on variable rate	1.50%
LIBOR | Maximum
Line of Credit Facility [Line Items]
Line of credit basis spread on variable rate	2.00%