Share-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended						0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended	0 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2013 Stock Options	Jan. 16, 2014 Stock Options Subsequent Event	Dec. 31, 2013 Stock Options Minimum	Dec. 31, 2013 Stock Options Maximum	Jan. 16, 2014 Restricted Stock Units (RSUs)	Dec. 31, 2013 Restricted Stock Units (RSUs)	Dec. 31, 2012 Restricted Stock Units (RSUs)	Dec. 31, 2011 Restricted Stock Units (RSUs)	Jan. 16, 2014 Restricted Stock Units (RSUs) Subsequent Event	Dec. 31, 2013 Restricted Stock Units (RSUs) Minimum	Jan. 16, 2014 Restricted Stock Units (RSUs) Performance Based Vesting [Member] Subsequent Event	Dec. 31, 2013 Share Based Compensation Arrangement Award	Dec. 31, 2013 Due to Changes in the Plan Scenario, Previously Reported	May 31, 2011 2011 Plan	Dec. 31, 2013 Prior Plans	Dec. 31, 2013 Stock Options, Restricted Stock Units or Stock Bonus Plans	Dec. 31, 2013 Stock Options and Restricted Stock Unit Plans
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Number of common stock reserved for future issuance	22,200,000																9,100,000		7,000,000	4,200,000	8,900,000	6,200,000
Number of common stock available for future grant	2,900,000
Share-based compensation, term				3 years	4 years			7 years	10 years
Restricted stock, vesting period	4 years						4 years	3 years	4 years	4 years					4 years
Share-based compensation, contractual term	10 years				10 years													7 years
Assumption estimated forfeiture rate	0.00%										0.00%
Weighted-average fair values of options granted	$ 6.55	$ 6.05	$ 4.14
Weighted average remaining contractual term for options outstanding	5 years 9 months 18 days
Share-based compensation expense	$ 6,819,000	$ 5,479,000	$ 2,918,000			$ 6,000,000					$ 800,000	$ 0	$ 500,000
Unrecognized compensation cost						8,800,000					2,400,000
Stock vesting period						2 years 1 month 6 days					3 years
Number of stock options exercisable	4,300,000
Stock options exercisable, weighted average exercise price	$ 7.30
Stock options exercisable, weighted-average remaining contractual term	4 years 10 months 24 days
Stock options exercised in period intrinsic value	6,000,000	943,000	423,000
Stock options intrinsic value of options outstanding and exercisable	15,600,000
Cash received from stock option exercises	5,300,000	731,000	286,000
Stock options granted	771,000	1,446,000	1,605,000				800,000
Share-based compensation, exercise price	$ 9.24	$ 8.50	$ 5.90				$ 19.59
Total intrinsic value vested in period											0	400,000	1,900,000
Intrinsic value outstanding											$ 3,500,000
Restricted stock units granted											379,000		50,000	400,000		500,000