Income Taxes (Reconciliation From Statutory Federal Income Tax Rate To Effective Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	35.00%	35.00%	35.00%
State tax on commercial operations, net of federal benefits	0.60%	0.50%	0.70%
Impact of international operations	(1.40%)	(2.60%)	0.00%
Domestic production deduction	(1.60%)	(1.90%)	(2.20%)
Domestic tax credits	(1.10%)	(0.70%)	(0.80%)
Contract close-outs	(2.90%)	0.00%	0.00%
Other, net	(0.90%)	(0.60%)	(1.50%)
Effective income tax rate	27.70%	29.70%	31.20%