XML 32 R36.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Comprehensive Income (AOCI Rollforward) (Details) (USD $) | 3 Months Ended
--- | ---
Mar. 31, 2015 | Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward] |  |  |
Balance at beginning of period | $ 11,313,015 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax | [1] |
Comprehensive Income | 74,674,373 us-gaap_ComprehensiveIncomeNetOfTax |  | 66,074,507 us-gaap_ComprehensiveIncomeNetOfTax
Balance at end of period | 8,803,947 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax |  | 19,483,799 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Foreign currency translation adjustments |  |  |
Accumulated Other Comprehensive Income (Loss) [Roll Forward] |  |  |
Balance at beginning of period | 1,403,899 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember |  | 2,507,922 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember
Other Comprehensive (loss) income before reclassifications | (942,974)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember |  | (91,250)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember
Amounts reclassified from accumulated other comprehensive income | 0 us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember |  | 0 us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember
Comprehensive Income | (942,974)us-gaap_ComprehensiveIncomeNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember |  | (91,250)us-gaap_ComprehensiveIncomeNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember
Balance at end of period | 460,925 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember |  | 2,416,672 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedTranslationAdjustmentMember
Unrealized gains on available-for-sale securities: |  |  |
Accumulated Other Comprehensive Income (Loss) [Roll Forward] |  |  |
Balance at beginning of period | 10,868,322 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember |  | 19,467,441 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Other Comprehensive (loss) income before reclassifications | (2,073,471)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember |  | 864,910 us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Amounts reclassified from accumulated other comprehensive income | 1,697,976 us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember |  | (3,265,224)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Comprehensive Income | (375,495)us-gaap_ComprehensiveIncomeNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember |  | (2,400,314)us-gaap_ComprehensiveIncomeNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Balance at end of period | 10,492,827 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember |  | 17,067,127 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Unrealized gains (losses) on derivatives |  |  |
Accumulated Other Comprehensive Income (Loss) [Roll Forward] |  |  |
Balance at beginning of period | (959,206)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember |  | 0 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
Other Comprehensive (loss) income before reclassifications | 0 us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember |  | 0 us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
Amounts reclassified from accumulated other comprehensive income | (1,190,599)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember |  | 0 us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
Comprehensive Income | (1,190,599)us-gaap_ComprehensiveIncomeNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember |  | 0 us-gaap_ComprehensiveIncomeNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
Balance at end of period | $ (2,149,805)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember |  | $ 0 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax / us-gaap_StatementEquityComponentsAxis = us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
[1] | Note: The condensed consolidated balance sheet at December 31, 2014 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

X
- Details
Name: | gntx_AccumulatedOtherComprehensiveIncomeLossRollForward
Namespace Prefix: | gntx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e681-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669686-108580 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 + Details
Name: | us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners. + References Reference 1: 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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Comprehensive Income -URI http://asc.fasb.org/extlink&oid=35737396 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e557-108580 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Net Income -URI http://asc.fasb.org/extlink&oid=6518256 + Details
Name: | us-gaap_ComprehensiveIncomeNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax, before reclassification adjustments of other comprehensive income (loss). + References No definition available. + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax of reclassification adjustments of other comprehensive income (loss). + References No definition available. + Details
Name: | us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedTranslationAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |