CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2017		42,865,407
Beginning balance at Dec. 31, 2017	$ 378,664	$ 13	$ 330,113	$ 46,184	$ 2,354
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of tax guidance				180	(180)
Stock-based compensation	271		271
Vesting of restricted stock units (in shares)		29,050
Vesting of restricted stock units	0
Shares withheld related to net settlement of equity awards (in shares)		(3,205)
Shares withheld related to net settlement of equity awards	(45)		(45)
Other comprehensive loss	(1,028)				(1,028)
Net income	(1,053)			(1,053)
Ending balance (in shares) at Mar. 31, 2018		42,891,252
Ending balance at Mar. 31, 2018	376,809	$ 13	330,339	45,311	1,146
Beginning balance (in shares) at Dec. 31, 2017		42,865,407
Beginning balance at Dec. 31, 2017	378,664	$ 13	330,113	46,184	2,354
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,347
Ending balance (in shares) at Jun. 30, 2018		42,893,982
Ending balance at Jun. 30, 2018	382,130	$ 13	330,995	50,711	411
Beginning balance (in shares) at Mar. 31, 2018		42,891,252
Beginning balance at Mar. 31, 2018	376,809	$ 13	330,339	45,311	1,146
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	667		667
Vesting of restricted stock units (in shares)		3,525
Vesting of restricted stock units	0
Shares withheld related to net settlement of equity awards (in shares)		(795)
Shares withheld related to net settlement of equity awards	(11)		(11)
Other comprehensive loss	(735)				(735)
Net income	5,400			5,400
Ending balance (in shares) at Jun. 30, 2018		42,893,982
Ending balance at Jun. 30, 2018	382,130	$ 13	330,995	50,711	411
Beginning balance (in shares) at Dec. 31, 2018		42,907,326
Beginning balance at Dec. 31, 2018	366,349	$ 13	332,330	34,187	(181)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	829		829
Vesting of restricted stock units (in shares)		93,014
Vesting of restricted stock units	0
Shares withheld related to net settlement of equity awards (in shares)		(13,657)
Shares withheld related to net settlement of equity awards	(130)		(130)
Other comprehensive loss	(2,098)				(2,098)
Net income	3,482			3,482
Ending balance (in shares) at Mar. 31, 2019		42,986,683
Ending balance at Mar. 31, 2019	368,432	$ 13	333,029	37,497	(2,107)
Beginning balance (in shares) at Dec. 31, 2018		42,907,326
Beginning balance at Dec. 31, 2018	366,349	$ 13	332,330	34,187	(181)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18,159
Ending balance (in shares) at Jun. 30, 2019		42,988,110
Ending balance at Jun. 30, 2019	382,658	$ 13	334,131	52,174	(3,660)
Beginning balance (in shares) at Mar. 31, 2019		42,986,683
Beginning balance at Mar. 31, 2019	368,432	$ 13	333,029	37,497	(2,107)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	1,110		1,110
Vesting of restricted stock units (in shares)		2,149
Vesting of restricted stock units	0
Shares withheld related to net settlement of equity awards (in shares)		(722)
Shares withheld related to net settlement of equity awards	(8)		(8)
Other comprehensive loss	(1,553)				(1,553)
Net income	14,677			14,677
Ending balance (in shares) at Jun. 30, 2019		42,988,110
Ending balance at Jun. 30, 2019	$ 382,658	$ 13	$ 334,131	$ 52,174	$ (3,660)