Equity (Share Activity) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 21, 2018	Sep. 11, 2018	Dec. 31, 2016
Equity, Treasury Stock [Line Items]
Share repurchase program, amount available for future share repurchases, value	$ 128,800,000
Treasury stock acquired, value	$ 602,000	$ 98,449,000
Treasury Stock, Common [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)	15,100	2,038,720
Treasury stock acquired, value	$ 602,000	$ 98,449,000
September 2018 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Share repurchase program, amount available for future share repurchases, value	28,800,000
Share repurchase program, amount authorized, value				$ 150,000,000
Treasury stock acquired, value	600,000
2016 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Share repurchase program, amount authorized, value					$ 100,000,000
Treasury stock acquired, value		$ 98,400,000
2016 Share Repurchase Program [Member] | Treasury Stock, Common [Member]
Equity, Treasury Stock [Line Items]
Treasury stock acquired (in shares)		2,000,000
December 2018 Share Repurchase Program [Member]
Equity, Treasury Stock [Line Items]
Share repurchase program, amount available for future share repurchases, value	$ 100,000,000
Share repurchase program, amount authorized, value			$ 100,000,000