Equity Incentive Compensation Plans and Other Long-term Incentive Programs - Stock Options and Nonvested Equity Shares, Equity Awards Granted (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 $ / shares shares	Sep. 30, 2019 $ / shares shares	Sep. 30, 2020 $ / shares shares	Sep. 30, 2019 $ / shares shares
Weighted Average Grant Date Fair Value (1)
Reverse stock split ratio			0.02
Nonvested Equity Shares
Units (1)
Beginning balance (in shares)	63,374	68,122	59,369	58,243
Granted (in shares)	0	120	40,572	36,954
Vested (in shares)	(2,384)	(7,120)	(33,754)	(33,711)
Forfeited or expired (in shares)	(2,034)	(1,462)	(7,231)	(1,826)
Ending balance (in shares)	58,956	59,660	58,956	59,660
Weighted Average Grant Date Fair Value (1)
Beginning balance (in dollars per share) | $ / shares	$ 103.45	$ 194.11	$ 190.74	$ 263.50
Granted (in dollars per share) | $ / shares	0	62.50	57.00	131.95
Vested (in dollars per share) | $ / shares	208.62	209.45	212.35	249.29
Forfeited or expired (in dollars per share) | $ / shares	61.09	239.81	74.39	241.44
Ending balance (in dollars per share) | $ / shares	$ 100.60	$ 190.90	$ 100.60	$ 190.90
Nonvested Performance Cash Units
Units (1)
Beginning balance (in shares)	108,796	57,372	51,521	18,191
Granted (in shares)			71,388	40,530
Forfeited or expired (in shares)	(7,714)	(5,851)	(21,827)	(7,200)
Ending balance (in shares)	101,082	51,521	101,082	51,521
Weighted Average Grant Date Fair Value (1)
Ending balance (in dollars per share) | $ / shares	$ 11.50	$ 79.50	$ 11.50	$ 79.50
Director
Units (1)
Beginning balance (in shares)	12,185	15,922	15,922	6,224
Granted (in shares)			10,618	12,862
Vested (in shares)			(12,767)	(3,164)
Forfeited or expired (in shares)			(1,588)	0
Ending balance (in shares)	12,185	15,922	12,185	15,922
Weighted Average Grant Date Fair Value (1)
Beginning balance (in dollars per share) | $ / shares	$ 86.22	$ 163.61	$ 163.61	$ 362.97
Granted (in dollars per share) | $ / shares			13.48	93.78
Vested (in dollars per share) | $ / shares			131.38	271.99
Forfeited or expired (in dollars per share) | $ / shares			12.69	0
Ending balance (in dollars per share) | $ / shares	$ 86.22	$ 163.61	$ 86.22	$ 163.61