Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($) shares
Statement of Stockholders' Equity [Abstract]
Other comprehensive income, tax expense (benefit) \| $	$ (794)
Purchase and retirement of common stock (in shares) \| shares	19,399,032

Number of shares that have been repurchased and retired during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Name Accounting Standards Codification
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration