Recent Accounting Pronouncements (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Increase of net cash used in investing activities	$ (58,488)	$ (56,929)
Accounting Standards Update 2016-18 [Member]
Increase of net cash used in investing activities		$ 33,100

Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3521-108585

Name:	us-gaap_NetCashProvidedByUsedInInvestingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration