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Income Taxes (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2017 | Mar. 31, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016
Operating Loss Carryforwards [Line Items] |  |  |  |  |  |
Income tax provision | $ 38,608 |  | $ 30,783 | $ 98,473 | $ 82,663 |
Effective income tax rates | 37.10% |  | 38.10% | 37.40% | 37.80% |
Actual income tax rates | 37.30% |  | 37.20% | 36.00% | 36.70% |
Unrecognized income tax benefits | $ 1,900 |  |  | $ 1,900 |  | $ 4,000
Unrecognized income tax benefits, if recognized, that would favorably affect the effective income tax rate | 700 |  |  | 700 |  | 2,200
Accrued interest expense related to unrecognized income tax benefits | 200 |  |  | 200 |  | $ 500
Interest income related to unrecognized income tax benefits |  |  | $ 100 | $ 300 | $ 100 |
Interest expense related to unrecognized income tax benefits | $ 100 |  |  |  |  |
Unrecognized tax benefits, decrease resulting from settlements with taxing authorities |  | $ 3,300 |  |  |  |

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- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: 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=84230637&loc=d3e32698-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 3: 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=84230637&loc=d3e32687-109319 + Details
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- Definition Amount of interest expense accrued for an underpayment of income taxes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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