Equity Compensation - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	May 07, 2013 Amended and Restated 2006 Equity Compensation Plan [Member]	May 07, 2013 2006 Equity Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares of common stock authorized for grant					7,350,000	4,000,000
Increase in number of shares of common stock authorized for grant					3,350,000
Capitalization of stock-based compensation cost	$ 0	$ 0	$ 0	$ 0
Pre-tax compensation expense for unvested stock-based compensation grants	17,700		17,700
Service period applicable to the grantees on a weighted-average basis, years			2 years 1 month 6 days
Number of RSUs vested in the period that were settled in cash				48,935
RSUs vested and settled in shares of common stock, amount	49	29	1,226	4,565
RSUs vested and settled in cash, amount				$ 3,073