Revisions to Condensed Consolidated Financial Statements (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Change In Accounting Estimate [Line Items]
Provision for (benefit from) income taxes	$ (5)	$ (2,709)	$ (2,963)	$ 105
Net loss from continuing operations	(23,978)	(15,406)	(16,566)	(1,280)
Net income (loss)	(23,978)	(14,761)	(16,107)	6,430
Basic Net Income (loss) Per Share:
Net loss per share from continuing operations		$ (0.09)		$ (0.01)
Basic net income (loss) per share		$ (0.08)		$ 0.04
Diluted net income (loss) per share:
Net loss per share from continuing operations		$ (0.09)		$ (0.01)
Diluted net income (loss) per share		$ (0.08)		$ 0.04
Comprehensive income (loss)	(25,601)	(14,896)	(16,015)	3,366
Prepaid expenses and other assets			(18,915)	4,188
Net cash provided by operating activities			117,469	121,424
As Previously Reported
Change In Accounting Estimate [Line Items]
Provision for (benefit from) income taxes		(3,384)		(1,025)
Net loss from continuing operations		(14,731)		(150)
Net income (loss)		(14,086)		7,560
Basic Net Income (loss) Per Share:
Net loss per share from continuing operations		$ (0.08)		$ 0.00
Basic net income (loss) per share		$ (0.08)		$ 0.04
Diluted net income (loss) per share:
Net loss per share from continuing operations		$ (0.08)		$ 0.00
Diluted net income (loss) per share		$ (0.08)		$ 0.04
Comprehensive income (loss)		(14,221)		4,496
Prepaid expenses and other assets				3,058
Net cash provided by operating activities				121,424
Adjustment
Change In Accounting Estimate [Line Items]
Provision for (benefit from) income taxes		675		1,130
Net loss from continuing operations		(675)		(1,130)
Net income (loss)		(675)		(1,130)
Basic Net Income (loss) Per Share:
Net loss per share from continuing operations		$ 0.00		$ (0.01)
Basic net income (loss) per share		$ 0.00		$ (0.01)
Diluted net income (loss) per share:
Net loss per share from continuing operations		$ 0.00		$ (0.01)
Diluted net income (loss) per share		$ 0.00		$ (0.01)
Comprehensive income (loss)		(675)		(1,130)
Prepaid expenses and other assets				$ 1,130