Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenues	$ 504,520	$ 471,231	$ 1,046,728	$ 887,685
Costs and Expenses:
Cost of operations	367,534	338,023	759,977	641,658
Research and development costs	4,029	5,332	8,632	10,506
Losses on asset disposals and impairments, net	299	151	299	151
Selling, general and administrative expenses	55,137	54,052	108,095	105,735
Total Costs and Expenses	426,999	397,558	877,003	758,050
Equity in Income of Investees	4,913	6,862	10,976	14,544
Operating Income	82,434	80,535	180,701	144,179
Other Income (Expense):
Interest income	61	137	292	552
Interest expense	(7,865)	(9,542)	(15,832)	(18,245)
Other – net	9,450	6,604	17,367	14,125
Total Other Income (Expense)	1,646	(2,801)	1,827	(3,568)
Income before Provision for Income Taxes	84,080	77,734	182,528	140,611
Provision for Income Taxes	19,684	18,734	42,512	32,501
Net Income	64,396	59,000	140,016	108,110
Net Income Attributable to Noncontrolling Interest	(138)	(122)	(259)	(254)
Net Income Attributable to BWX Technologies, Inc.	$ 64,258	$ 58,878	$ 139,757	$ 107,856
Basic:
Net Income Attributable to BWX Technologies, Inc. (in usd per share)	$ 0.67	$ 0.62	$ 1.46	$ 1.13
Diluted:
Net Income Attributable to BWX Technologies, Inc. (in usd per share)	$ 0.67	$ 0.62	$ 1.46	$ 1.13
Shares used in the computation of earnings per share (Note 10):
Basic (in shares)	95,457,629	95,357,311	95,434,990	95,306,210
Diluted (in shares)	95,633,571	95,677,204	95,694,972	95,749,280