Basis of Presentation - Additional Information (Detail)	0 Months Ended	3 Months Ended
	Mar. 31, 2015 Location	Mar. 31, 2015	Dec. 31, 2014	Oct. 28, 2014	Mar. 31, 2014	Apr. 28, 2015
Basis Of Presentation [Line Items]
Number of locations	62
Common stock, shares authorized	80,000,000	80,000,000	80,000,000		80,000,000
Stock repurchase program, number of shares authorized to be repurchased				1,500,000
Stock repurchase program expiration date		Sep. 30, 2017
Minimum number of shares that company is required to repurchase		0
Stock repurchased under authorization		0
Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	8
Subsequent Event [Member]
Basis Of Presentation [Line Items]
Common stock, shares authorized						120,000,000
Abilene [Member]
Basis Of Presentation [Line Items]
Number of locations	11
Abilene [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Cleburne [Member]
Basis Of Presentation [Line Items]
Number of locations	2
Stephenville [Member]
Basis Of Presentation [Line Items]
Number of locations	2
Stephenville [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Granbury [Member]
Basis Of Presentation [Line Items]
Number of locations	2
San Angelo [Member]
Basis Of Presentation [Line Items]
Number of locations	3
San Angelo [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Weatherford [Member]
Basis Of Presentation [Line Items]
Number of locations	3
Mineral Wells [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Hereford [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Sweetwater [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Sweetwater [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Eastland [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Ranger [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Rising Star [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Cisco [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Southlake [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Grapevine [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Aledo [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Willow Park [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Brock [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Alvarado [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Beaumont [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Burleson [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Keller [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Trophy Club [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Boyd [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Bridgeport [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Decatur [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Roby [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Trent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Merkel [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Clyde [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Moran [Member]
Basis Of Presentation [Line Items]
Number of locations	1
New Waverly [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Albany [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Midlothian [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Glen Rose [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Odessa [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Odessa [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Waxahachie [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Acton [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Fort Worth [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Fort Worth [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Orange [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Orange [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Newton [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Port Arthur [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Vidor [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Mauriceville [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Huntsville [Member]
Basis Of Presentation [Line Items]
Number of locations	1
Lubbock [Member] | Subsidiary of Common Parent [Member]
Basis Of Presentation [Line Items]
Number of locations	1