Stock-Based Compensation - Changes in the Number and Weighted-Average Grant-Date Fair Value of Non-Vested Stock Option Awards (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Beginning balance	8,073	7,858	6,802
Stock option awards granted, options	3,277	1,617	1,830
Stock option awards forfeited/cancelled, Options Outstanding	(1,801)	(1,052)	(584)
Options Outstanding, Ending balance	8,986	8,073	7,858
Weighted Average Exercise Price, Beginning balance	$ 6.09	$ 6.21	$ 6.66
Stock option awards granted, Weighted Average Grant-Date Fair Value	$ 3.05	$ 4.65	$ 3.97
Stock option awards forfeited, Weighted Average Grant-Date Fair Value	$ 7.22	$ 6.26	$ 5.99
Weighted Average Exercise Price, Ending balance	$ 4.99	$ 6.09	$ 6.21
Non Vested Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Beginning balance	2,435
Stock option awards granted, options	3,277
Stock option awards vested, options	(1,215)
Stock option awards forfeited/cancelled, Options Outstanding	(288)
Options Outstanding, Ending balance	4,209
Weighted Average Exercise Price, Beginning balance	$ 3.18
Stock option awards granted, Weighted Average Grant-Date Fair Value	$ 0.80
Stock option awards vested, Weighted Average Grant-Date Fair Value	$ 2.87
Stock option awards forfeited, Weighted Average Grant-Date Fair Value	$ 2.00
Weighted Average Exercise Price, Ending balance	$ 1.50