Preferred Stock (Details) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($) $ / shares shares
Temporary Equity [Line Items]
Preferred Stock, Shares Issued | shares	120,000
Preferred Stock, Liquidation Preference, Value | $	$ 120.0
Preferred Stock, Value, Issued | $	$ 142.0
Preferred Stock, Dividend Rate, Percentage	8.00%
Preferred stock annual dividends | $	$ 9.6
Convertible Preferred Stock, Shares Issued upon Conversion | shares	44.9438
Convertible preferred stock, total number of shares issued upon conversion | shares	5,393,000
Preferred Stock Initial Conversion Price per Share | $ / shares	$ 22.25