Dividends (Dividends Paid In Total And Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 02, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividends [Abstract]
Total paid		$ 137,886	$ 137,201	$ 136,386
Per share (in dollars per share)		$ 2.4925	$ 2.4825	$ 2.4725
Maximum dividend payable without prior permission of DOI of states domicile		$ 167,000
Payments of ordinary dividends		$ 109,000	$ 111,000	$ 133,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Quarterly dividend declared (in dollars per share)	$ 0.6250