Stockholders' Equity - Additional Information (Detail) - USD ($)			1 Months Ended									3 Months Ended		9 Months Ended		40 Months Ended
	Jan. 01, 2015	Dec. 09, 2014	Sep. 30, 2015	Aug. 31, 2015	Jul. 31, 2015	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Mar. 31, 2015	Feb. 28, 2015	Jan. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Oct. 28, 2015	Jul. 28, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized (shares)			75,000,000									75,000,000		75,000,000		75,000,000
Common stock par value (usd per share)			$ 0.0001									$ 0.0001		$ 0.0001		$ 0.0001
Preferred stock authorized (shares)			25,000,000									25,000,000		25,000,000		25,000,000
Preferred stock par value (usd per share)			$ 0.0001									$ 0.0001		$ 0.0001		$ 0.0001
Common stock outstanding (shares)			21,069,454									21,069,454		21,069,454		21,069,454			21,978,762
Preferred stock outstanding (shares)			0									0		0		0			0
Total stock based compensation												$ 394,000	$ 1,106,000	$ 1,497,000	$ 2,816,000
Declaration date														Oct. 28, 2015
Dividend rate (usd per share)																		$ 0.125
Record date														Nov. 18, 2015
Payment date														Dec. 10, 2015
Dividends declared																		$ 5,200,000
Total number of shares purchased (shares)			163,708	156,408	182,826	138,432	38,898	0	230,532	1,234	16,031			928,069
Expected amount for dividends and/or common stock repurchases			$ 26,000,000									26,000,000		$ 26,000,000		$ 26,000,000
Increase (decrease) in additional paid-in capital														(13,400,000)
Additional paid-in capital			$ 113,313,000									$ 113,313,000		$ 113,313,000		$ 113,313,000			$ 126,678,000
Common Stock Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase authority	$ 15,000,000.0
Total number of shares purchased (shares)			163,708	156,408	182,826	138,432	38,898	0	10,202	1,234	16,031	502,942		707,739	707,739
Treasury stock acquired, value												$ 8,300,000		$ 11,800,000
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)																5,820
2015 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based compensation												$ 301,000	$ 0	$ 1,220,000	$ 0
2015 LTIP [Member] | Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		36 months
Granted (shares)	254,777											4,974		6,122		260,899
Granted	$ 4,400,000											$ 100,000		$ 200,000
Forfeited (shares)												9,792				9,792
Shares outstanding (shares)			251,107			255,925						251,107		251,107		251,107
2015 LTIP [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	251,107
Subsequent Event [Member] | Common Stock Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase authority																	$ 10,000,000.0