Commitments and Contingencies (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Accrual for estimated environmental remediation costs	$ 21,079	$ 21,365	$ 21,651	$ 13,241	$ 13,942
Additions to accrual	0	$ 0	$ 10,000	$ 0
Environmental liability, next 12 month	12,500
Environmental liability thereafter	$ 8,600