Summary of Significant Accounting Policies (Inventory) (Narrative) (Details)	Dec. 31, 2016	Dec. 31, 2015
Inventory Policy [Abstract]
Percentage of FIFO Inventory	55.00%	55.00%
Percentage of LIFO Inventory	15.00%	15.00%
Percentage of average cost inventory	30.00%	30.00%

The percentage of weighted average cost inventory present at the reporting date when inventory is valued using different valuation methods.

No definition available.

Name:	us-gaap_PercentageOfWeightedAverageCostInventory
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant