Share Repurchase Programs (Details) - USD ($)	2 Months Ended	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Mar. 31, 2016	Jan. 17, 2017
Equity [Abstract]
Authorized amount				$ 200,000,000
Value repurchased	$ 15,100,000	$ 15,151,000	$ 110,985,000
Shares repurchased	360,000
Shares repurchased, average cost per share (in dollars per share)	$ 42.06