Consolidated Statement of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Dividends declared per share (in dollars per share)	$ 0.54	$ 0.54	$ 0.54
Tax expense (benefit) on pension liability	$ 25	$ 14	$ (95)
Retained Deficit [Member]
Dividends declared per share (in dollars per share)	$ 0.54	$ 0.54	$ 0.54
Accumulated Other Comprehensive Income (Loss) [Member]
Tax expense (benefit) on pension liability	$ 25	$ 14	$ 95

Amount of tax expense (benefit) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e640-108580

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