Statement of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Retained Earnings (Deficit)	Paid-in Capital / Common stock held in treasury	Accumulated Other Comprehensive Income/(Loss)
Beginning balance (in shares) at Dec. 31, 2017			19,538
Beginning balance at Dec. 31, 2017		$ 333,559	$ 20	$ 374,366	$ (38,629)	$ (2,198)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		31,251		31,251
Other comprehensive income, (net of tax)	[1]	436				436
Effects of U.S. enacted Tax Cuts and Jobs Act	[1]	(293)		(293)
Effect of adoption | Accounting Standards Update 2016-16		360		360
Equity-based compensation (in shares)			75
Equity-based compensation		3,649			3,649
Dividends declared ($1.44 per share)	[2]	(28,293)		(28,293)
Ending balance (in shares) at Sep. 30, 2018			19,613
Ending balance at Sep. 30, 2018		340,669	$ 20	377,391	(34,980)	(1,762)
Beginning balance at Jun. 30, 2018						(1,715)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		14,090
Other comprehensive income, (net of tax)		(47)
Ending balance (in shares) at Sep. 30, 2018			19,613
Ending balance at Sep. 30, 2018		340,669	$ 20	377,391	(34,980)	(1,762)
Beginning balance (in shares) at Dec. 31, 2018			19,613
Beginning balance at Dec. 31, 2018		335,515	$ 20	372,815	(34,304)	(3,016)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		16,546		16,546
Other comprehensive income, (net of tax)		(2,621)				(2,621)
Effect of adoption | Accounting Standards Update 2016-02	[3]	11,897		11,897
Equity-based compensation (in shares)			78
Equity-based compensation		4,934			4,934
Dividends declared ($1.44 per share)	[4]	(28,373)		(28,373)
Ending balance (in shares) at Sep. 30, 2019			19,691
Ending balance at Sep. 30, 2019		337,898	$ 20	372,885	(29,370)	(5,637)
Beginning balance at Jun. 30, 2019						(5,803)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		6,451
Other comprehensive income, (net of tax)		166
Ending balance (in shares) at Sep. 30, 2019			19,691
Ending balance at Sep. 30, 2019		$ 337,898	$ 20	$ 372,885	$ (29,370)	$ (5,637)

[1] Includes the impact of ASU 2018-02, which transferred those amounts from accumulated other comprehensive income (loss) to retained earnings. See Note 16 to the Condensed Consolidated Financial Statements.

[2] $0.48 per share declared February 2018, May 2018, and July 2018

[3] On the transition to ASC 842 effective January 1, 2019, a deferred gain (net of taxes) related to a sale leaseback transaction was credited to Retained Earnings. See Note 8 to the Condensed Consolidated Financial Statements.

[4] $0.48 per share declared February 2019, April 2019, and August 2019