Retirement Plan - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Sale Of Subsidiary [Abstract]
Employers' sponsors contribution retirement plan	90.00%
Contribution to retirement plan percentage of employee contribution	100.00%
Percentage of employee contribution to retirement plan	5.00%
Employers' sponsors contribution retirement plan amount	$ 0.2	$ 0.1	$ 0.1