7. Stockholders' Equity (Details)	12 Months Ended				12 Months Ended				3 Months Ended
	Dec. 31, 2013 Common Class A [Member]	Dec. 31, 2012 Common Class A [Member]	Dec. 31, 2011 Common Class A [Member]	Dec. 31, 2010 Common Class A [Member]	Dec. 31, 2013 Common Class B [Member]	Dec. 31, 2012 Common Class B [Member]	Dec. 31, 2011 Common Class B [Member]	Dec. 31, 2010 Common Class B [Member]	Jun. 30, 2012 Treasury Class-A [Member]	Jun. 30, 2012 Treasury Class B [Member]
Class of Stock [Line Items]
Shares, Issued	23,681,000	23,333,000	23,020,000	22,677,000	5,097,000	5,150,000	5,165,000	5,175,000
Stock Issued During Period, Shares, Conversion of Convertible Securities	80,000	59,000	39,000		(80,000)	(59,000)	(39,000)
Stock Issued During Period, Shares, New Issues	269,000	253,000	304,000		27,000	44,000	28,000
Treasury Stock, Shares, Acquired									122	917
Voting Rights, Number of Vote Entitled Per Share	0.1				1
Election Percentage for Board of Directors	25.00%				75.00%