Income Taxes Changes in Unrecognized Tax Benefit (Including Interest and Penalties) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 3,400
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	3,658	$ 3,497	$ 343
Additions for tax positions for current year	793	1,208	2,879
Additions for tax positions for prior years	1,593	228	396
Lapse of the applicable statute of limitations	(46)	(25)	(121)
Reduction for tax positions for prior years	(287)	(1,250)
Ending Balance	5,711	3,658	3,497
Unrecognized Tax Benefits Before Interest And Penalties
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	3,357	3,397	252
Additions for tax positions for current year	793	1,208	2,879
Additions for tax positions for prior years	1,427	0	349
Lapse of the applicable statute of limitations	(37)	(20)	(83)
Reduction for tax positions for prior years	(271)	(1,228)
Ending Balance	5,269	3,357	3,397
Interest & Penalties
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	301	100	91
Additions for tax positions for current year	0	0	0
Additions for tax positions for prior years	166	228	47
Lapse of the applicable statute of limitations	(9)	(5)	(38)
Reduction for tax positions for prior years	(16)	(22)
Ending Balance	$ 442	$ 301	$ 100