v2.4.0.8

Basis of Presentation - Effects of Prior Period Errors Consolidated Statements of Changes in Shareholders' Equity (Detail) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended
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Dec. 31, 2012 | Sep. 30, 2012 | Jun. 30, 2012 | Mar. 31, 2012 | Dec. 31, 2011 | Sep. 30, 2011 | Jun. 30, 2011 | Mar. 31, 2011 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2012 Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2011 Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2010 Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2012 Retained Earnings [Member] | Dec. 31, 2011 Retained Earnings [Member] | Dec. 31, 2010 Retained Earnings [Member] | Dec. 31, 2012 As Previously Reported [Member] | Sep. 30, 2012 As Previously Reported [Member] | Jun. 30, 2012 As Previously Reported [Member] | Mar. 31, 2012 As Previously Reported [Member] | Dec. 30, 2011 As Previously Reported [Member] | Sep. 30, 2011 As Previously Reported [Member] | Jun. 30, 2011 As Previously Reported [Member] | Mar. 31, 2011 As Previously Reported [Member] | Dec. 31, 2012 As Previously Reported [Member] | Dec. 31, 2011 As Previously Reported [Member] | Dec. 31, 2010 As Previously Reported [Member] | Dec. 31, 2012 As Previously Reported [Member] Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2011 As Previously Reported [Member] Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2010 As Previously Reported [Member] Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2012 As Previously Reported [Member] Retained Earnings [Member] | Dec. 31, 2011 As Previously Reported [Member] Retained Earnings [Member] | Dec. 31, 2010 As Previously Reported [Member] Retained Earnings [Member] | Dec. 31, 2012 As Adjusted [Member] | Sep. 30, 2012 As Adjusted [Member] | Jun. 30, 2012 As Adjusted [Member] | Mar. 31, 2012 As Adjusted [Member] | Dec. 31, 2011 As Adjusted [Member] | Sep. 30, 2011 As Adjusted [Member] | Jun. 30, 2011 As Adjusted [Member] | Mar. 31, 2011 As Adjusted [Member] | Dec. 31, 2012 As Adjusted [Member] | Dec. 31, 2011 As Adjusted [Member] | Dec. 31, 2010 As Adjusted [Member] | Dec. 31, 2012 As Adjusted [Member] Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2011 As Adjusted [Member] Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2010 As Adjusted [Member] Paid-in Capital in Excess of par Value [Member] | Dec. 31, 2012 As Adjusted [Member] Retained Earnings [Member] | Dec. 31, 2011 As Adjusted [Member] Retained Earnings [Member] | Dec. 31, 2010 As Adjusted [Member] Retained Earnings [Member]
Condensed Financial Statements, Captions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning Balance |  |  |  | $ 548,144 |  |  |  | $ 473,996 | $ 548,144 | $ 473,996 | $ 351,218 | $ 291,950 | $ 249,902 | $ 222,882 | $ 293,887 | $ 251,261 | $ 151,612 |  |  |  | $ 560,188 |  |  |  | $ 487,212 | $ 560,188 | $ 487,212 | $ 359,311 | $ 291,950 | $ 248,693 | $ 222,882 | $ 305,931 | $ 265,686 | $ 159,705 |  |  |  | $ 548,144 |  |  |  | $ 473,996 | $ 548,144 | $ 473,996 | $ 351,218 | $ 291,950 | $ 249,902 | $ 222,882 | $ 293,887 | $ 251,261 | $ 151,612
Excess tax benefit from exercise of stock options, SARs and restricted stock grants |  |  |  |  |  |  |  |  | 29,684 | 26,241 | 9,254 | 29,684 | 26,241 | 9,254 |  |  |  |  |  |  |  |  |  |  |  |  | 27,450 | 8,045 |  | 27,450 | 8,045 |  |  |  |  |  |  |  |  |  |  |  |  | 26,241 | 9,254 |  | 26,241 | 9,254 |  |  |
Net income | 112,200 | 111,900 | 132,000 | 107,900 | 110,100 | 107,500 | 108,600 | 88,800 | 463,962 | 414,959 | 292,883 |  |  |  | 463,962 | 414,959 | 292,883 | 117,881 | 117,779 | 133,368 | 108,162 | 105,357 | 108,022 | 111,180 | 88,019 | 477,190 | 412,578 | 299,215 |  |  |  | 477,190 | 412,578 | 299,215 | 112,207 | 111,873 | 131,951 | 107,931 | 110,072 | 107,459 | 108,601 | 88,827 | 463,962 | 414,959 | 292,883 |  |  |  | 463,962 | 414,959 | 292,883
Ending Balance | $ 395,483 |  |  |  | $ 548,144 |  |  |  | $ 395,483 | $ 548,144 | $ 473,996 | $ 303,975 | $ 291,950 | $ 249,902 | $ 123,096 | $ 293,887 | $ 251,261 | $ 420,755 |  |  |  |  |  |  |  | $ 420,755 | $ 560,188 | $ 487,212 | $ 303,975 | $ 291,950 | $ 248,693 | $ 148,368 | $ 305,931 | $ 265,686 | $ 395,483 |  |  |  | $ 548,144 |  |  |  | $ 395,483 | $ 548,144 | $ 473,996 | $ 303,975 | $ 291,950 | $ 249,902 | $ 123,096 | $ 293,887 | $ 251,261

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- Definition Tax benefit associated with any equity-based compensation plan other than an employee stock ownership plan (ESOP). The tax benefit results from the deduction by the entity on its tax return for an award of stock that exceeds the cumulative compensation cost for common stock or preferred stock recognized for financial reporting. Includes any resulting tax benefit that exceeds the previously recognized deferred tax asset (excess tax benefits). + References Reference 1: 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=6928386&loc=d3e21463-112644 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=6959260&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 740 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6419406&loc=d3e23524-113945 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph 62 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28, 29, 30 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.18) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 20 -Article 9 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.22) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 10, 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e565-108580 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 19 -Article 5 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Other Comprehensive Income -URI http://asc.fasb.org/extlink&oid=6519514 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Net Income -URI http://asc.fasb.org/extlink&oid=6518256 Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A7 -Appendix A Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph d -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 14: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 15: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.19) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 16: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 4.E) -URI http://asc.fasb.org/extlink&oid=6228006&loc=d3e74512-122707 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E 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 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 + Details
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