Income Taxes (Details) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended		12 Months Ended
	Feb. 29, 2016	Mar. 31, 2017	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2012	Dec. 31, 2015
Income Tax Examination [Line Items]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		$ (1,100,000)			$ (900,000)		$ 0
Interest Expense (Income) related to unrecognized tax benefits		(200,000)			(900,000)
Unrecognized Tax Benefits [Abstract]
Unrecognized tax benefit - Permanent tax positions		4,600,000			4,500,000
Unrecognized tax benefit - Temporary tax positions		24,300,000			24,200,000
Total unrecognized tax benefit		28,900,000			28,700,000
NOL and tax credit carryforwards		(6,100,000)			(5,900,000)
Upper bound of decrease in unrecognized tax benefit that is reasonably possible		10,000,000
Amounts accrued for penalties related to unrecognized tax benefits		0			$ 0
Internal Revenue Service (IRS)
Tax Audits [Abstract]
Year(s) under examination				2012 and 2013		2010 and 2011
Year of carryback claim under examination						2009
Potential Tax Adjustments		$ 14,000,000
Earliest year subject to examination		2009
State Jurisdiction (Texas)
Tax Audits [Abstract]
Year(s) under examination	2009 and 2010
Earliest year subject to examination			2009