Equity (Accumulated Other Comprehensive Loss) (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Accumulated Other Comprehensive Loss [Line Items]
Accumulated other comprehensive losses	$ 74,737		$ 72,351
Unrealized foreign currency translation gains (losses)	5,624	$ (22,028)
Other comprehensive loss, unrecognized unrealized fair market value losses, net of tax	8,010	$ 0
Equity Method Investees [Member] | Waha JVs [Member] | Interest Rate Swaps [Member]
Accumulated Other Comprehensive Loss [Line Items]
Other comprehensive loss, unrecognized unrealized fair market value losses, before tax	13,000
Other comprehensive loss, unrecognized unrealized fair market value losses, net of tax	$ 8,000