Share Repurchase Plan (Details) - USD ($)	3 Months Ended			6 Months Ended		38 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	May 31, 2016
Equity [Abstract]
Amount authorized by the company's Board of Directors (not more than)							$ 30,000,000.0
Common stock repurchased under share repurchase program (in shares)	348,974		0	421,716	0	726,899
Amount of program-to-date purchases	$ 11,300,000	$ 2,300,000				$ 21,100,000
Average cost per share (in dollars per share)	$ 32.33					$ 29.01