Share Repurchase Authorization - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016	Oct. 31, 2018
Shares Repurchase Authorization [Line Items]
Stock repurchase, number of shares authorized to be repurchased	3,000,000
Shares of common stock repurchased	1,061,000	615,000
Amount available for future repurchase	$ 33,239,000
Common Stock [Member]
Shares Repurchase Authorization [Line Items]
Shares of common stock repurchased	1,061,000
Number of share repurchases programs	2
Maximum [Member]
Shares Repurchase Authorization [Line Items]
Stock repurchase, authorized amount			$ 40,000,000