Preferred and Common Stock - Additional Information (Detail) $ / shares in Units, $ in Thousands								1 Months Ended					3 Months Ended			9 Months Ended	12 Months Ended			14 Months Ended	23 Months Ended	31 Months Ended
	Oct. 05, 2016 $ / shares shares	Aug. 31, 2016 USD ($)	Jul. 31, 2015 shares	Jul. 23, 2015 shares	Jul. 22, 2015 shares	Jun. 16, 2014 shares	Jun. 15, 2014 shares	Aug. 31, 2016 USD ($)	Aug. 30, 2016 USD ($)	Jul. 30, 2015 shares	Nov. 30, 2014 shares	Nov. 29, 2014 shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 $ / shares shares	Sep. 30, 2014 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Oct. 04, 2016 $ / shares shares	Oct. 04, 2016 $ / shares shares	Oct. 04, 2016 $ / shares shares	Mar. 31, 2014 shares	Mar. 30, 2014 shares	Dec. 31, 2013 shares
Class of Stock [Line Items]
Public offering of preferred stock																$ 1,250,000
Depository shares | shares																25,000,000
Interest in preferred stock																0.1
Proceeds from public offering																$ 1,213,000
Reverse stock split ratio	0.33																0.33
Common stock outstanding | shares	400,000,000												438,519,780	1,310,160,141	1,216,663,661		438,519,780	1,310,160,141	1,216,663,661	1,300,000,000	1,300,000,000	1,300,000,000			1,071,011,162
Common stock, par value per share | $ / shares	$ 1.00																			$ 1.00	$ 1.00	$ 1.00
Common stock decrease																	$ (877,000)
Additional capital increase (decrease)																	$ 877,000
Common Stock authorized | shares	600,000,000																			1,800,000,000	1,800,000,000	1,800,000,000
Retirement of treasury stock		$ 25,000						$ 76,000	$ 76,000
Common stock issued, in shares | shares													438,519,780				438,519,780
Common stock, dividends yield | $ / shares													$ 0.06				$ 0.36	$ 0.12	$ 0.12
Dividends paid per share | $ / shares													$ 0.09	$ 0.09	$ 0.09		$ 0.36	$ 0.36	$ 0.36
Common stock reserved for future issuance | shares													45,000,000				45,000,000
Stock options granted, vesting period																	3 years	3 years	3 years
Stock options granted, contractual term																	10 years
Stock awards, vesting period																	Three-year
Stock based compensation expense, before tax																	$ 86,000	$ 92,000	$ 87,000
Stock based compensation expense, after tax																	$ 51,000	$ 51,000	$ 47,000
Stock based compensation expense, stock awards percentage																	80.00%	80.00%	80.00%
Unrecognized compensation costs on non-vested stock option grants (pretax)													$ 45,000				$ 45,000
Unrecognized compensation costs on non-vested stock option awards (pretax)													0				$ 0
Unrecognized compensation costs on non-vested awards, weighted average period of recognition in years																	1 year 6 months
Expense related to the acceleration of expense related to retirement-eligible employees																	$ 19,000	$ 15,000	$ 11,000
Stock option granted, Fair value																	$ 4,780	$ 10,070	$ 6,400
Average risk-free interest rate																	2.06%
Dividend yield																	1.10%
Volatility																	44.50%	36.50%	35.00%
Annual pre- and post-vesting forfeitures																	7.00%
Exercise behavior																	60.00%
Life (years)																	5 years 8 months 12 days
Number of options, Outstanding weighted average remaining contractual life																	5 years 11 months 27 days
Total intrinsic value of options outstanding													$ 10,000				$ 10,000
Stock options vested | shares																	8,900,000
Stock option exercisable | shares																	8,900,000
Weighted average remaining contractual life, vested and exercisable																	4 years 9 months
Weighted average exercise price, vested and exercisable | $ / shares													$ 26.23				$ 26.23
Total intrinsic value of options vested and exercisable													$ 200				$ 200
Cash received from option exercises																	4,000	$ 25,000	$ 150,000
Total tax benefit realized from these exercises																	0	6,000	28,000
Total intrinsic value of options exercised																	$ 1,000	$ 19,000	$ 84,000
Preferred Class A [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized | shares													660,000				660,000
Preferred stock par value | $ / shares													$ 100				$ 100
Cumulative dividend preference per share | $ / shares																	$ 3.75
Preferred stock, shares outstanding | shares													546,024	546,024			546,024	546,024
Preferred stock dividend declared | $ / shares																	$ 3.75	$ 3.75	$ 3.75
Preferred Class B [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized | shares													10,000,000				10,000,000
Preferred stock par value | $ / shares													$ 1				$ 1
Preferred stock, shares outstanding													$ 2,500	$ 2,500			$ 2,500	$ 2,500
Preferred stock dividend declared | $ / shares																	$ 26.8750	$ 26.8750	$ 7.53993
RTI [Member]
Class of Stock [Line Items]
Number of common stock shares issued in a part of acquisition | shares	29,000,000		29,000,000	87,397,414	29,132,471					87,000,000										87,000,000
Firth Rixson [Member]
Class of Stock [Line Items]
Number of common stock shares issued in a part of acquisition | shares						36,523,010	12,174,337
Issuance of common stock | shares	12,000,000																				37,000,000
5.25% Convertible Notes Due 2014 [Member]
Class of Stock [Line Items]
Common stock issued, in shares | shares																							30,000,000	89,000,000
Debt Instrument, Interest Rate, Stated Percentage															5.25%				5.25%				5.25%
Stock option exercisable | shares																			30,000,000			89,000,000
5.25% Convertible Notes Due 2014 [Member] | Firth Rixson [Member]
Class of Stock [Line Items]
Issuance of common stock | shares											12,000,000	37,000,000
Common Stock [Member]
Class of Stock [Line Items]
Retirement of treasury stock								76,000	76,000								$ 76,000
Additional Capital [Member]
Class of Stock [Line Items]
Retirement of treasury stock								$ 2,563,000	$ 2,563,000								$ 2,563,000
Maximum [Member]
Class of Stock [Line Items]
Preferred stock conversion price | $ / shares													$ 15.6981				$ 15.6981
Minimum [Member]
Class of Stock [Line Items]
Preferred stock conversion price | $ / shares													13.0817				13.0817
Class B Mandatory Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Percentage ownership																5.375%
Mandatory Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock par value | $ / shares																$ 1
Preferred stock liquidation preference | $ / shares																$ 500
Preferred share | shares																2,500,000
Preferred stock dividend declared | $ / shares																	$ 26.8750
Preferred stock conversion date																	Oct. 01, 2017
Mandatory Convertible Preferred Stock [Member] | Minimum [Member] | Anti - Dilution Adjustments [Member]
Class of Stock [Line Items]
Preferred stock conversion price | $ / shares													$ 13.0817				$ 13.0817