Income Taxes (Income Tax Rates) (Details)	3 Months Ended	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Income Tax [Line Items]
Effective tax rate	30.50%	36.50%	34.50%		35.70%
Federal statutory tax rate	21.00%	35.00%		35.00%
Income Tax Rate Capital Gains	20.00%	20.00%	20.00%		20.00%
Maximum
Income Tax [Line Items]
Period in which adjustments related to the Federal Tax Cuts and Jobs Act of 2017 needed to be made	12 months

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration