Change In Accounting Estimate (Narrative) (Details) - Change In Salvage Value [Member] - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Change in Accounting Estimate [Line Items]
Decrease in salvage values	$ 6.9	$ 0.6
Increase in depreciation expense after adjustment	$ 0.1
Period between salvage value reviews	3 years

The change during the period, from the beginning balance of accumulated depreciation, depletion and amortization (relating to property, plant and equipment) to the ending balance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Name:	us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration