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Common Stock - Summary of Information and Changes in Stock Options with Regard to Stock Option Plans (Detail) - USD ($) | 12 Months Ended
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Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] |  |  |
Number of shares under stock option, Beginning of the year | 15,430,307 | 10,881,133 | 11,535,566
Number of Shares Granted | 3,672,411 | 5,746,153 | 3,389,547
Number of Shares Cancelled | (1,517,065) | (886,356) | (498,967)
Number of Shares Exercised | (146,593) | (310,623) | (1,977,665)
Number of shares under stock option, End of the year | 17,439,060 | 15,430,307 | 10,881,133
Number of stock options, Vested or expected to vest | 17,212,352 |  |
Number of stock options, Exercisable | 9,828,897 | 7,498,414 | 5,903,712
Weighted Average Exercise Price, Beginning of year | $ 59.50 | $ 61.22 | $ 58.36
Weighted Average Exercise Price, Stock Options Granted | 28.26 | 54.74 | 69.00
Weighted Average Exercise Price, Stock Options Cancelled | 49.95 | 62.73 | 70.32
Weighted Average Exercise Price, Stock Options Exercised | 28.53 | 22.56 | 53.56
Weighted Average Exercise Price, End of the year | 54.08 | 59.50 | 61.22
Weighted Average Exercise Price, Stock options vested or expected to vest | 54.08 |  |
Weighted Average Exercise Price, Stock Options, Exercisable | $ 61.56 | $ 60.30 | $ 55.06
Weighted Average Remaining Contractual Term, Outstanding | 6 years 9 months 4 days | 5 years 1 month 28 days |
Weighted Average Remaining Contractual Term, Vested | 6 years 9 months 4 days |  |
Weighted Average Remaining Contractual Term, Exercisable | 5 years 5 months 1 day |  |
Stock Options Aggregate Intrinsic Value, Beginning | $ 5,894,977 |  |
Stock Options Aggregate Intrinsic Value, Granted | $ 0 |  |
Stock Options Aggregate Intrinsic Value, Ending | $ 37,928,494 | $ 5,894,977 |
Stock Options Average Aggregate Intrinsic Value, Vested or expected to Vest | 37,408,874 |  |
Stock Options Average Aggregate Intrinsic Value, Exercisable | $ 6,700,856 |  |

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- Definition Share Based Compensation Arrangements By Share Based Payment Award Options Outstanding Weighted Average Remaining Contractual Term. + References No definition available. + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Net number of share options (or share units) granted during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The grant-date intrinsic value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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