Shareholders' Equity Stock Repurchase Authorization (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Mar. 14, 2019	Jan. 31, 2019
Stock Repurchase Authorization [Abstract]
Stock repurchase program, authorized amount				$ 50,000	$ 25,000
Stock repurchased during period (in shares)	364,000	165,000	529,396
Stock repurchased, average cost per share (in dollars per share)			$ 47.22
Stock repurchased during period, value	$ 17,186	$ 7,814	$ 25,000
Stock repurchase program, remaining authorized repurchase amount			$ 25,000