Share Repurchase Program and Treasury Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Share Repurchase Program and Treasury Stock (Textuals) [Abstract]
Remaining Amount to Repurchase under the program	$ 1,233,400
Shares Purchased Under Share Repurchase Program	25,400,000
Treasury Stock, Value, Acquired, Cost Method	$ 249,997	$ 247,500	$ 494,966
Number of shares repurchased	(732,245)	(777,248)
Average price of share repurchased, per share	$ 341.39	$ 318.38
Exercise of stock options and restricted stock units, shares reissued	131,737	233,593