Shareholders' Equity and Redeemable Non-controlling Interests, Shareholders' Equity, Treasury shares (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Increase (Decrease) in Treasury Stock [Roll Forward]
Beginning balance (in shares)	6,568,745
Purchase of ordinary shares (in shares)	50,685
Ending balance (in shares)	6,215,824
Treasury shares [Member]
Increase (Decrease) in Treasury Stock [Roll Forward]
Beginning balance (in shares)	6,568,745	24,513,619
Share-based compensation (in shares)	(225,367)	(256,140)
Employee stock purchase plan (in shares)	(178,239)	(83,473)
Purchase of ordinary shares (in shares)	50,685	5,648,900
Ending balance (in shares)	6,215,824	29,822,906