Allowance for Doubtful Accounts (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]      
Balance at beginning of period $ 6,128 $ 2,636 $ 1,232
Bad debt expense 3,275 6,517 2,206
Write-offs, net (3,875) (3,025) (802)
Balance at end of period $ 5,528 $ 6,128 $ 2,636