XML 16 R33.htm IDEA: XBRL DOCUMENT v2.4.0.8
Fair Value Measurements - Additional Information (Detail) (USD $)
 3 Months Ended
Mar. 31, 2014
Fair Value Disclosures [Abstract]  
Percent of credit loss 6.60%
Rate of return required 5.00%
Estimated timeframe for auctions of securities minimum 3 years
Estimated timeframe for auctions of securities maximum 5 years
Percentage of liquidity risk premium 5.00%
Increase or decrease in the liquidity risk premium 1.00%
Increase or decrease, respectively, the fair value of the Failed Auction Securities $ 400,000