Capital Stock - Schedule of Unamortized Value of Restricted Stock (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Amortization Expense [Line Items]
Total Unamortized value	$ 806	$ 407
4th Quarter 2013 [Member]
Amortization Expense [Line Items]
Total Unamortized value	100
1st Quarter 2014 [Member]
Amortization Expense [Line Items]
Total Unamortized value	100
2nd Quarter 2014 [Member]
Amortization Expense [Line Items]
Total Unamortized value	100
3rd Quarter 2014 [Member]
Amortization Expense [Line Items]
Total Unamortized value	100
4th Quarter 2014 [Member]
Amortization Expense [Line Items]
Total Unamortized value	100
1st Quarter 2015 [Member]
Amortization Expense [Line Items]
Total Unamortized value	96
2nd Quarter 2015 [Member]
Amortization Expense [Line Items]
Total Unamortized value	54
3rd Quarter 2015 [Member]
Amortization Expense [Line Items]
Total Unamortized value	54
4th Quarter 2015 [Member]
Amortization Expense [Line Items]
Total Unamortized value	54
1st Quarter 2016 [Member]
Amortization Expense [Line Items]
Total Unamortized value	$ 48