UNAUDITED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Earnings	Accumulated Other Comprehensive Income
Balance, December 31, 2013 at Dec. 31, 2013	$ 6,909,729	$ 476	$ (1,987,207)	$ 4,592,979	$ 4,218,752	$ 84,729
Balance (in shares) at Dec. 31, 2013		(61,265)	(9,257)
Increase (Decrease) in Stockholders' Equity
Net income applicable to common stockholders	331,218				331,218
Foreign currency translation adjustments, net of tax of $1,137	7,914					7,914
Unrealized gain on marketable securities, net of tax of $49	108					108
Reclassification adjustment for convertible debt in mezzanine	4,215			4,215
Exercise of stock options and vesting of restricted stock units and performance share units	7,693	1		7,692
Exercise of stock options and vesting of restricted stock units and/or performance share units (in shares)		206
Repurchase of common stock	(96,660)		(96,660)
Repurchase of common stock (in shares)			(72)
Stock-based compensation and other stock-based payments	39,412			39,412
Conversion of debt	281	1		280
Conversion of debt (in shares)		143
Excess tax benefit on stock-based compensation	5,499			5,499
Balance, March 31, 2014 at Mar. 31, 2014	$ 7,209,409	$ 478	$ (2,083,867)	$ 4,650,077	$ 4,549,970	$ 92,751
Balance (in shares) at Mar. 31, 2014		(61,614)	(9,329)