Equity Incentive Plans - Summary of Nonvested Restricted Stock and Restricted Stock Units Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares Nonvested, Beginning Balance	1,015	1,910	1,441
Number of Shares, Granted			1,003
Number of Shares, Vested	(487)	(840)	(512)
Number of Shares, Forfeited or Cancelled	(34)	(55)	(22)
Number of Shares Nonvested Ending Balance	494	1,015	1,910
Weighted-Average Grant Date Fair Value Beginning Balance	$ 2.43	$ 2.81	$ 4.43
Weighted-Average Grant Date Fair Value, Granted			$ 1.78
Weighted-Average Grant Date Fair Value, Vested	$ 2.16	$ 3.37	$ 5.28
Weighted-Average Grant Date Fair Value, Forfeited or Cancelled	$ 1.78	$ 1.97	$ 3.69
Weighted-Average Grant Date Fair Value Ending Balance	$ 2.73	$ 2.43	$ 2.81