Share-Based Compensation Expense (Schedule of Share-Based Compensation Expense Showing Amount Attributable to Each Category) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share Based Compensation [Abstract]
Amortization of restricted stock awards and restricted stock unit awards	$ 4,142	$ 1,663	$ 6,782	$ 4,437
Amortization of stock option awards	2	24	23	58
Discount given on employee stock purchase transactions through our Employee Stock Purchase Plan	68	73	176	179
Share-based compensation expense from continuing operations	4,212	1,760	6,981	4,674
Share-based compensation expense from discontinued operations		329		792
Total share-based compensation expense	$ 4,212	$ 2,089	$ 6,981	$ 5,466

Allocated share based compensation expense (benefit) from discontinued operations.

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- Definition

Allocated share based compensation expense from continuing operations.

+ References

No definition available.

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- Definition

Share-based compensation discount to employees on ESPP.

+ References

No definition available.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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- Definition

Amount of noncash expense for award of restricted stock or unit under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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- References

No definition available.

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- Definition

Amount of noncash expense for option under share-based payment arrangement.

+ References

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