Income Tax (Pre-tax Income Foreign and Domestic) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Domestic									$ 493,328	$ 768,857	$ 473,223
Income (Loss) from Continuing Operations before Income Taxes, Foreign									251,467	239,676	162,031
Income before income taxes	$ 206,743	$ 140,137	$ 213,790	$ 184,125	$ 276,743	$ 231,815	$ 300,535	$ 199,440	$ 744,795	$ 1,008,533	$ 635,254