Stockholder's Equity - Activity Relating to Common Shares (Detail)	9 Months Ended
	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance, as of December 31, 2013	43,641,000
Balance, as of December 31, 2013	(8,275,000)
Balance, as of December 31, 2013	35,366,000
Conversion of preferred stock	64,938
Balance, as of September 30, 2014	44,955,000
Balance, as of September 30, 2014	(10,666,000)
Balance, as of September 30, 2014	34,289,000
Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance, as of December 31, 2013	43,641,000
Conversion of preferred stock	65,000
Options exercised	1,788,000
Restricted stocks grants	950,000
Shares cancelled	(1,489,000)
Balance, as of September 30, 2014	44,955,000
Treasury Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance, as of December 31, 2013	(8,275,000)
Shares repurchased	(2,391,000)
Shares acquired through cashless exercise	(1,489,000)	[1]
Shares cancelled	1,489,000
Balance, as of September 30, 2014	(10,666,000)
Stock Compensation Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance, as of December 31, 2013	35,366,000
Conversion of preferred stock	65,000
Shares repurchased	(2,391,000)
Options exercised	1,788,000
Restricted stocks grants	950,000
Shares acquired through cashless exercise	(1,489,000)	[1]
Balance, as of September 30, 2014	34,289,000

[1] All shares acquired represent shares tendered to cover the strike price for options and tax withholdings on the intrinsic value of options exercised or restricted stock vested. These shares have been cancelled by the Company.