Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance, shares at Dec. 31, 2012		297,811,000
Beginning Balance at Dec. 31, 2012	$ 1,964,094	$ 2,978	$ 950,338	$ 1,010,019	$ 759
Net income	311,623	0	0	311,623	0
Other comprehensive income (loss)	19,252	$ 0	0	0	19,252
Restricted stock units vested, shares		595,000
Restricted stock units vested, value	0	$ 6	(6)	0	0
Stock-based compensation expense	$ 22,036	$ 0	22,036	0	0
Stock options exercised, shares	2,399,419	2,399,000
Exercise of stock options, value	$ 15,392	$ 24	15,368	0	0
Excess tax benefit from stock-based payments	18,348	$ 0	18,348	0	0
Ending Balance, shares at Dec. 31, 2013		300,805,000
Ending Balance at Dec. 31, 2013	2,350,745	$ 3,008	1,006,084	1,321,642	20,011
Net income	381,519	0	0	381,519	0
Other comprehensive income (loss)	(60,236)	$ 0	0	0	(60,236)
Restricted stock units vested, shares		975,000
Restricted stock units vested, value	0	$ 10	(10)	0	0
Stock-based compensation expense	$ 22,021	$ 0	22,021	0	0
Stock options exercised, shares	1,687,700	1,688,000
Exercise of stock options, value	$ 9,324	$ 17	9,307	0	0
Tax withholdings related to net share settlements of stock-based compensation awards, value	(443)	(15)	(443)
Excess tax benefit from stock-based payments	17,727	$ 0	17,727	0	0
Ending Balance, shares at Dec. 31, 2014		303,453,000
Ending Balance at Dec. 31, 2014	2,720,657	$ 3,035	1,054,686	1,703,161	(40,225)
Net income	423,223	0	0	423,223	0
Other comprehensive income (loss)	(65,245)	$ 0	0	0	(65,245)
Restricted stock units vested, shares		840,000
Restricted stock units vested, net of shares withheld for employee tax	(4,341)	$ 8	(4,349)	0	0
Stock-based compensation expense	$ 21,336	$ 0	21,336	0	0
Stock options exercised, shares	1,425,075	1,425,000
Exercise of stock options, value	$ 8,863	$ 14	8,849	0	0
Tax withholdings related to net share settlements of stock-based compensation awards, shares		(144,000)
Tax withholdings related to net share settlements of stock-based compensation awards, value	(3,936)	$ (2)	(3,934)	0	0
Excess tax benefit from stock-based payments	14,125	$ 0	14,125	0	0
Ending Balance, shares at Dec. 31, 2015		305,574,000
Ending Balance at Dec. 31, 2015	$ 3,114,682	$ 3,055	$ 1,090,713	$ 2,126,384	$ (105,470)