Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Warranty and overhaul reserves
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 92,064	$ 87,849	$ 60,593
Charged/ (credited) to expense	28,947	35,418	34,110
Charged/(credited) to other accounts	56,753	(1,762)	12,717
Deductions from reserves	38,772	29,441	19,571
Balance at end of period	138,992	92,064	87,849
Allowance for doubtful accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	5,614	6,270	5,707
Charged/ (credited) to expense	3,635	2,026	4,200
Charged/(credited) to other accounts	0	0	0
Deductions from reserves	1,909	2,682	3,637
Balance at end of period	7,340	5,614	6,270
Valuation allowance-taxes
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	12,623	1,818	3,332
Charged/ (credited) to expense	3,405	7,024	(1,514)
Charged/(credited) to other accounts	5,390	3,781	0
Deductions from reserves	0	0	0
Balance at end of period	21,418	12,623	1,818
Merger and restructuring reserve
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	622	686	775
Charged/ (credited) to expense	0	0	0
Charged/(credited) to other accounts	0	0	0
Deductions from reserves	59	64	89
Balance at end of period	$ 563	$ 622	$ 686