Equity (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 25, 2016
Equity, Treasury Stock [Line Items]
Treasury stock acquired, value		$ 100,000
Share reissuances, treasury stock, value			$ 104,427
Convertible Debt [Member]
Equity, Treasury Stock [Line Items]
Share reissuances, treasury stock, value			$ 104,400
Treasury Stock, Common [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)		5,217,693
Treasury stock acquired, value		$ 100,000
Share reissuances, treasury stock (in shares)			6,590,975
Share reissuances, treasury stock, value			$ 104,427
Treasury Stock, Common [Member] | Convertible Debt [Member]
Equity, Treasury Stock [Line Items]
Share reissuances, treasury stock (in shares)			6,600,000
2016 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Share repurchase program, amount authorized, value				$ 100,000
2016 Share Repurchase Program [Member] | Treasury Stock, Common [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	0
2014 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired, value		$ 100,000
2014 Share Repurchase Program [Member] | Treasury Stock, Common [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)		5,200,000