Consolidated Statements of Comprehensive Income (Loss) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income available (loss attributable) to common stockholders	$ 17,986,000	$ 13,080,000	$ (28,883,000)
Other comprehensive income:
Unrealized gains on cash flow hedging instruments (net of tax effect of $5,258 in 2016)	7,875,000
Less: Interest expense on derivatives recognized into earnings (net of tax effect of $(163) in 2016)	(244,000)
Total other comprehensive income	7,631,000	0
Comprehensive income (loss)	$ 25,617,000	$ 13,080,000	$ (28,883,000)