Stock-based Compensation and Outstanding Awards - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options, Outstanding, Beginning balance \| shares	3,530,635
Stock Options, Granted \| shares	534,929
Stock Options, Forfeited \| shares	(60,586)
Stock Options, Exercised or settled \| shares	(15,077)
Stock Options, Outstanding, Ending balance \| shares	3,989,901
Stock Options, Exercisable at December 31, 2015 \| shares	2,437,226
Weighted average exercise price, Outstanding, Beginning balance	$ 30.86
Weighted average exercise price, Granted	22.44
Weighted average exercise price, Forfeited	29.51
Weighted average exercise price, Exercised or settled	13.98
Weighted average exercise price, Outstanding, Ending balance	29.81
Weighted average exercise price, Exercisable at December 31, 2015	31.04
Weighted Average Grant-Date Fair Value	$ 8.06
Aggregate intrinsic value, Outstanding, Ending balance \| $	$ 0

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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-Publisher FASB
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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options.

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Number of share options (or share units) exercised during the current period.

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