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Common Stock Repurchase Programs - Additional Information (Detail) - USD ($) |  |  | 1 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Mar. 16, 2015 | Dec. 17, 2014 | Oct. 31, 2015 | Jul. 31, 2015 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Mar. 31, 2015 | Dec. 31, 2014 | Oct. 31, 2014
Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Common stock repurchased |  |  |  |  | $ 70,192,000 | $ 61,828,000 | $ 235,051,000 |  |  |
Common stock authorized for repurchase |  |  |  |  |  |  |  |  |  | $ 600,000,000
Common Stock [Member] |  |  |  |  |  |  |  |  |  |
Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Repurchased common stock, shares |  |  |  |  | 1,038,000 | 946,000 | 3,365,000 |  |  |
Common stock repurchased |  |  |  |  | $ 10,000 | $ 9,000 | $ 34,000 |  |  |
Restricted Stock [Member] |  |  |  |  |  |  |  |  |  |
Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Number of shares withheld to satisfy minimum statutory tax withholding obligations |  |  |  |  | 38,257 | 46,490 |  |  |  |
Amount withheld to satisfy minimum statutory tax withholding obligations |  |  |  |  | $ 2,100,000 | $ 3,200,000 |  |  |  |
Accelerated Share Repurchase (ASR) Agreements [Member] |  |  |  |  |  |  |  |  |  |
Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Repurchased common stock, shares | 2,200,000 | 2,500,000 | 300,000 | 300,000 |  |  |  |  |  |
Common stock repurchased | $ 200,000,000 | $ 200,000,000 |  |  |  |  |  |  |  |
Common stock purchase |  |  |  |  |  |  |  | $ 200,000,000 | $ 200,000,000 |

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- Definition Common Stock [Line Items] + References No definition available. + Details
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- Definition Amount of cash receipt from (payment to) bank; or stock received from (issuance to) bank in the settlement of the accelerated share repurchase agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 25 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6405686&loc=d3e22802-112653 + Details
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- Definition The amount of adjustment to stockholders' equity associated with an employee's income tax withholding obligation as part of a net-share settlement of a share-based award. + References No definition available. + Details
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- Definition For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer. + References No definition available. + Details
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- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
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- Definition Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644 + Details
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- Definition Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Details
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