Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

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Percentage of vesting of share-based compensation awards.

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Stock-Based Compensation Programs - PCEQs (Details) - PCEQs - shares	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jun. 30, 2018
Stock-Based Compensation Programs
Granted (in shares)	261,174	237,452
Vesting period			3 years
Minimum
Stock-Based Compensation Programs
Percent of participant PCEQ award assigned that determines the number of shares available at vesting date	0.00%	0.00%
Maximum
Stock-Based Compensation Programs
Percent of participant PCEQ award assigned that determines the number of shares available at vesting date	200.00%	200.00%