Business Acquisitions (Narrative) (Details) - USD ($) $ in Thousands, shares in Millions			3 Months Ended	9 Months Ended
	Apr. 04, 2016	Aug. 03, 2015	Dec. 31, 2016	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016
Atmel Corporation
Business Acquisition [Line Items]
Cash paid for shares	$ 2,980,000
Shares issued as part of acquisition	10.1
Value of shares issued as part of acquisition	$ 486,100
Transaction and other fees incurred in transaction	14,900
Non cash consideration of certain share-based payment awards	7,500
Total consideration transferred	3,470,000
Liabilities assumed	708,100		$ 708,055	$ 708,055	$ 717,161
Payments to acquire businesses portion funded by foreign subsidiaries cash balances	2,040,000
Payments to acquire businesses portion funded by additional lIne of credit borrowings	940,000
Net deferred tax liability for future amortization expense of acquired intangible assets	$ 158,700
Revenue of acquiree included in statement of income since the acquisition date			263,200	756,300
Net loss of acquiree included in statements of income since the acquisition date			34,700	294,100
Net deferred tax assets acquired in a business combination			$ 49,360	$ 49,360	$ 49,360
Micrel Incorporated
Business Acquisition [Line Items]
Cash paid for shares		$ 430,000
Shares issued as part of acquisition		8.6
Non cash consideration of certain share-based payment awards		$ 4,100
Total consideration transferred		816,200
Liabilities assumed						$ 138,419
Net deferred tax liability for future amortization expense of acquired intangible assets		99,700
Consideration transferred. cash paid for vested employee stock awards		13,100
Net deferred tax assets acquired in a business combination		$ 11,400