Long-Term Debt - Long-Term Debt, Including Amortizing Principal and Interest Payments (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Total long-term debt	$ 35,633	$ 45,397
Total amortizing	19,833
Total non-amortizing loans	15,800
Amortizing Loans August 28, 2014 [Member]
Debt Instrument [Line Items]
Monthly Installment	18
Fixed Rate	2.66%
Maturity Date	Aug. 28, 2014
Total amortizing	246
Amortizing Loans March 02, 2015 [Member]
Debt Instrument [Line Items]
Monthly Installment	67
Fixed Rate	3.44%
Maturity Date	Mar. 02, 2015
Total amortizing	1,302
Amortizing Loans March 31, 2015 [Member]
Debt Instrument [Line Items]
Monthly Installment	13
Fixed Rate	3.48%
Maturity Date	Mar. 31, 2015
Total amortizing	273
Amortizing Loans April 02, 2018 [Member]
Debt Instrument [Line Items]
Monthly Installment	10
Fixed Rate	3.83%
Maturity Date	Apr. 02, 2018
Total amortizing	531
Amortizing Loans March 13, 2023 [Member]
Debt Instrument [Line Items]
Monthly Installment	186
Fixed Rate	4.69%
Maturity Date	Mar. 13, 2023
Total amortizing	17,481
Non Amortizing Loans September 22, 2017 [Member]
Debt Instrument [Line Items]
Fixed Rate	2.36%
Maturity Date	Sep. 22, 2017
Total non-amortizing loans	6,500
Non Amortizing Loans December 02, 2019 [Member]
Debt Instrument [Line Items]
Floating Rate	1.84%
Maturity Date	Dec. 02, 2019
Total non-amortizing loans	3,000
Non Amortizing Loans December 19, 2019 [Member]
Debt Instrument [Line Items]
Floating Rate	1.48%
Maturity Date	Dec. 19, 2019
Total non-amortizing loans	$ 6,300