Shareholders' Equity (Narrative) (Details) shares in Thousands, $ in Thousands	6 Months Ended	93 Months Ended
	Jun. 30, 2016 USD ($) shares	Jun. 30, 2016 USD ($) shares
Shareholders’ Equity [Abstract]
Stock repurchase program, authorized amount	$ 2,000,000	$ 2,000,000
Acquisition of treasury stock (shares) | shares	1,469	6,521
Acquisition of treasury stock (value), total	$ 676,934	$ 1,860,862
Value of common shares remaining to be repurchased	$ 139,504	$ 139,504