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Reconciliation of Statutory Federal Income Tax (Benefit) Expense Reported in Net Income to Combined Actual Income Tax (Benefit) Expense (Parenthetical) (Detail) - USD ($) | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Reconciliation of Provision of Income Taxes [Line Items] |  |  |
Statutory federal income tax rate | 35.00% | 35.00% | 35.00%
Income tax (benefit) expense, adjustment to deferred taxes | $ (1,400,000) | $ 600,000.0 |

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- Definition Reconciliation of Provision of Income Taxes [Line Items] + References No definition available. + Details
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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 + Details
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- Definition Amount of income tax expense (benefit) from continuing operations attributable to an adjustment of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319 + Details
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