v2.4.0.8
10. Income taxes: (Details) - Expiration of Credit Taxes (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2008
Dec. 31, 2007
Dec. 31, 2006
Dec. 31, 2005
Dec. 31, 2004
Dec. 31, 2003
Dec. 31, 2002
Dec. 31, 2001
Dec. 31, 2000
Dec. 31, 1999
Dec. 31, 2033
Expiration of Credit Taxes [Abstract]                                
$ 2,568,328 $ 1,638,421 $ 1,746,615 $ 822,678 $ 1,723,146 $ 1,599,919 $ 1,479,818 $ 1,532,322 $ 1,304,283 $ 1,250,783 $ 2,775,900 $ 2,503,951 $ 3,681,189 $ 4,425,866 $ 88,022  
2033 2032 2031 2030 2029 2028 2027 2026 2025 2024 2023 2022 2021 2020 2019  
Total $ 29,141,241                             $ 29,141,241