Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Equity [Abstract]
Treasury shares, acquired, tax burden	3,676		14,428
Treasury shares, acquired, value, tax burden	$ 400		$ 1,700
Treasury Stock, Shares, Acquired	58,676		69,428
Treasury Stock, Value, Acquired, Cost Method	$ 6,100		$ 7,400
Treasury Stock, Value	$ 82,708		$ 82,708		$ 80,773
Stock Issued During Period, Shares, Treasury Stock Reissued	11,180		46,402
Cash dividends per share (in dollars per share)	$ 0.55	$ 0.55	$ 1.10	$ 1.10
Dividends declared (in dollars per share)	$ 0.55