Income Taxes - Other Matters (Details) $ in Millions	12 Months Ended
Dec. 31, 2017 USD ($)
Income Tax Disclosure [Abstract]
Tax benefit from remeasurement of deferred tax liabilities	$ 2.0

Amount of income tax benefit for remeasurement of deferred tax liability from change in tax rate pursuant to Tax Cuts and Jobs Act.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration