Quarterly Data (Unaudited) - Tax Benefit from Sale of New Jersey State Net Operating Losses (Details) $ in Millions	3 Months Ended
Mar. 31, 2018 USD ($)
New Jersey \| Technology Business Tax Certificate Program
Sale of New Jersey Net Operating Losses
Tax benefit	$ 0.5

Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.7)
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
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-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration