Organization and Summary of Significant Accounting Policies (Computation of Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Basic earnings per share:
Net income	$ 66,748	$ 51,517	$ 40,755	$ 27,658	$ 43,178	$ 29,432	$ 26,335	$ 23,696	$ 186,678	$ 122,641	$ 266,799
Weighted-average common shares outstanding									428,822	425,889	420,544
Basic earnings per share (in USD per share)	$ 0.16	$ 0.12	$ 0.10	$ 0.06	$ 0.10	$ 0.07	$ 0.06	$ 0.06	$ 0.44	$ 0.29	$ 0.63
Diluted earnings per share:
Net income	$ 66,748	$ 51,517	$ 40,755	$ 27,658	$ 43,178	$ 29,432	$ 26,335	$ 23,696	$ 186,678	$ 122,641	$ 266,799
Shares used in computation:
Weighted-average common shares outstanding									428,822	425,889	420,544
Employee stock options									9,830	10,567	11,350
Weighted-average number of shares									438,652	436,456	431,894
Diluted earnings per share (in USD per share)	$ 0.15	$ 0.12	$ 0.09	$ 0.06	$ 0.10	$ 0.07	$ 0.06	$ 0.05	$ 0.43	$ 0.28	$ 0.62