CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Paid-in Capital	Retained Earnings	Class A Common Stock	Class B Non-Voting Common Stock
Balance at Dec. 31, 2012	$ 2,332,621	$ 2,198,501	$ 133,111	$ 991	$ 18
Balance (in shares) at Dec. 31, 2012				99,417,998	1,829,339
Increase (Decrease) in Shareholders' Equity
Issuance of restricted stock units (in shares)				954,980
Exercise of stock options (in shares)				167
Stock based compensation expense	17,839	17,839
Cash dividends	(7,609)		(7,609)
Tax withholding related to exercise of stock options and vesting of restricted stock units	(13,609)	(13,609)
Tax withholding related to exercise of stock options and vesting of restricted stock units (in shares)				(448,182)
Net income	131,564		131,564
Balance at Sep. 30, 2013	$ 2,460,806	$ 2,202,731	$ 257,066	$ 991	$ 18
Balance (in shares) at Sep. 30, 2013				99,924,963	1,829,339