Condensed Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Jun. 30, 2013	$ 238,162	$ 279	$ 118,190	$ 141,427	$ (21,961)	$ 227	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	16,863			16,858			5
Other comprehensive income (loss)	(175)					(175)
Payments to Acquire Interest in Joint Venture	700						700
Exercise of stock options	602		(376)		978
Tax effect of exercised stock options and vesting of deferred shares	1,075		1,075
Issuance of deferred shares	0		(4,361)		4,361
Treasury shares sold to Employee Stock Purchase Plan	38		0		38
Other treasury share purchases	(1,638)				(1,638)
Stock-based compensation expense	2,515		2,515
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2013	258,142	279	117,043	158,285	(18,222)	52	705
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Jun. 30, 2014	282,283	279	119,777	177,237	(16,595)	(182)	1,767
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(176)			9,200			(9,376)
Other comprehensive income (loss)	(3,271)					(3,271)
Exercise of stock options	364		(287)		651
Tax effect of exercised stock options and vesting of deferred shares	1,731		1,731
Issuance of deferred shares	0		(4,584)		4,584
Treasury shares sold to Employee Stock Purchase Plan	134		47		87
Other treasury share purchases	(2,439)				(2,439)
Stock-based compensation expense	3,168		3,168
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2014	$ 281,794	$ 279	$ 119,852	$ 186,437	$ (13,712)	$ (3,453)	$ (7,609)