Stock-Based Compensation and Other Benefit Plans - Stock Appreciation Rights Activity (Details) - Stock Appreciation Rights (SARs) [Member]	12 Months Ended
Dec. 31, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding at beginning of period (in shares)	43,000
Exercised (in shares)	(18,900)
Expired or cancelled (in shares)	(24,100)
Outstanding at end of period (in shares)	0

Number of non-option equity instruments exercised by participants.

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- Definition

Number of shares under non-option equity instrument agreements that were either cancelled or expired.

+ References

+ Details

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- Definition

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Details

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