Allowance for Doubtful Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts
Balance, beginning of year	$ 3,780	$ 4,585	$ 4,700
Provision (net of recovery)	1,001	(23)	2,169
Amounts written off, net of recoveries	(1,095)	(782)	(2,284)
Balance, end of year	$ 3,686	$ 3,780	$ 4,585