CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings
Beginning Balance at Dec. 31, 2012	$ 251,419	$ 2	$ 125,212	$ 126,205
Beginning Balance (shares) at Dec. 31, 2012		21,701,353
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	27,530			27,530
Issuance of common stock under the Equity Plan	539		539
Issuance of common stock under the Equity Plan (shares)		41,702
Purchased and retired common stock and other	(1,532)		(1,532)
Purchased and retired common stock and other (shares)		(108,459)
Amortization of stock based compensation	3,045		3,045
Cash distributions declared	(11,051)			(11,051)
Issuance of restricted common stock under the Equity Plan (shares)		17,745
Ending Balance at Dec. 31, 2013	269,950	$ 2	127,264	142,684
Ending Balance (shares) at Dec. 31, 2013		21,652,341
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	20,745			20,745
Issuance of common stock under the Equity Plan	85		85
Issuance of common stock under the Equity Plan (shares)		5,820
Issuance of common stock for vested restricted stock units under the Equity Plan (shares)		559,689
Purchased and retired common stock and other	(99)		(99)
Amortization of stock based compensation	3,753		3,753
Cash distributions declared	(11,050)			(11,050)
Common stock repurchase program	(4,325)		(4,325)
Common stock repurchase program (shares)		(263,772)
Issuance of restricted common stock under the Equity Plan (shares)		24,684
Ending Balance at Dec. 31, 2014	279,059	$ 2	126,678	152,379
Ending Balance (shares) at Dec. 31, 2014		21,978,762
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	84,235			84,235
Issuance of common stock under the Equity Plan	(3,824)		(3,824)
Issuance of common stock for vested restricted stock units under the Equity Plan (shares)		217,211
Purchased and retired common stock and other	721		721
Amortization of stock based compensation	1,868		1,868
Cash distributions declared	(13,498)			(13,498)
Common stock repurchase program	$ (15,008)		(15,008)
Common stock repurchase program (shares)	(897,177)	(897,177)
Issuance of restricted common stock under the Equity Plan (shares)		21,887
Ending Balance at Dec. 31, 2015	$ 333,553	$ 2	$ 110,435	$ 223,116
Ending Balance (shares) at Dec. 31, 2015		20,886,261