Stock-Based Compensation and Stock Repurchases (Summary of Restricted Stock Units Granted) (Details) - Restricted Stock Units (RSUs) [Member]	6 Months Ended
Jun. 30, 2017 shares
RSU Grants	131,297
Vested	43,398
Unvested	87,899
March 10, 2016 [Member]
RSU Grants	62,528
Vested	41,992
Unvested	20,536
April 11, 2016 [Member]
RSU Grants	5,625
Vested	1,406
Unvested	4,219
March 23, 2017 [Member]
RSU Grants	63,144
Unvested	63,144
Director [Member]
RSU Grants	65,828
Director [Member] \| March 10, 2016 [Member]
RSU Grants	35,147
Director [Member] \| March 23, 2017 [Member]
RSU Grants	30,681
Management [Member]
RSU Grants	65,469
Management [Member] \| March 10, 2016 [Member]
RSU Grants	27,381
Management [Member] \| April 11, 2016 [Member]
RSU Grants	5,625
Management [Member] \| March 23, 2017 [Member]
RSU Grants	32,463

Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant