Consolidated Statements Of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income	Treasury Stock [Member]
BALANCE, Shares at Dec. 31, 2016		16,445,000
Balance at beginning of period at Dec. 31, 2016	$ 404,410	$ 178	$ 289,422	$ 265,543	$ (76,261)	$ (74,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	11,789			11,789
Other comprehensive loss, net of tax	39,531				39,531
Common stock dividends paid	(2,507)			(2,507)
Stock options exercised, Shares		18,000
Stock options exercised	707		707
Conversion of restricted stock units, Shares		39,000
Conversion of restricted stock units	297	$ (1)	296
Share-based compensation	3,807		3,807
Repurchase of common stock, Shares						(3,283,000)
Measurement period change in fair value of common stock to acquire a business	(143,767)	$ 33	(143,734)			$ 0
BALANCE, Shares at Dec. 31, 2017		19,785,000
Balance at end of period at Dec. 31, 2017	601,974	$ 212	438,721	274,243	(36,730)	(74,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	173		755	(582)
Net income	(39,384)			(39,384)
Other comprehensive loss, net of tax	(33,009)			0	(33,009)
Stock options exercised, Shares		18,000
Stock options exercised	690	$ 0	690
Conversion of restricted stock units, Shares		42,000
Conversion of restricted stock units	(291)	$ 0	291
Share-based compensation	4,971		4,971
Repurchase of common stock, Shares		0
Measurement period change in fair value of common stock to acquire a business	$ (3,783)	$ 0	(3,783)			0
BALANCE, Shares at Dec. 31, 2018	19,845,205	19,845,000
Balance at end of period at Dec. 31, 2018	$ 528,993	$ 212	440,890	232,102	(69,739)	(74,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	(2,757)			(2,757)
Net income	(133,935)			(133,935)	0
Other comprehensive loss, net of tax	(10,528)				(10,528)
Stock options exercised, Shares		6,000
Stock options exercised	253	$ 0	253
Conversion of restricted stock units, Shares		61,000
Conversion of restricted stock units	64	$ (1)	(65)
Share-based compensation	$ 5,579		5,579
BALANCE, Shares at Dec. 31, 2019	19,912,362	19,912,000
Balance at end of period at Dec. 31, 2019	$ 391,411	$ 213	$ 446,657	99,280	$ (80,267)	$ (74,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 1,113			$ 1,113