Significant Accounting Policies - Additional Information (Details) (USD $)	3 Months Ended	12 Months Ended			3 Months Ended
	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Ziplist
Accounting Policies [Line Items]
Goodwill impairment	$ 44,300,000	$ 0	$ 44,257,000	$ 0
Proceeds from sale of investments					1,200,000
Realized gain on sale of investments					$ 1,200,000
Securities excluded from computation of diluted earnings per share		5,445,252	5,883,719	7,345,060